EURO-WARE 178C GPS Receiver User Manual

GPSMAP 178/178C
chartplotter & depth-finder
owner’s manual
© Copyright 2004 Garmin Ltd. or its subsidiaries
Garmin International, Inc.
1200 East 151st Street,
Olathe, Kansas 66062, U.S.A.
Tel. 913/397.8200 or 800/800.1020
Fax 913/397.8282
Garmin (Europe) Ltd.
Unit 5, The Quadrangle, Abbey Park
Industrial Estate, Romsey, SO51 9DL, U.K.
Tel. 44/0870.8501241
Fax 44/0870.8501251
Garmin Corporation
No. 68, Jangshu 2nd Road, Shijr, Taipei
County, Taiwan
Tel. 886/2.2642.9199
Fax 886/2.2642.9099
All rights reserved. Except as expressly provided herein, no part of this manual may be reproduced, copied, transmitted, disseminated, downloaded or stored in any storage
medium, for any purpose without the express prior written consent of Garmin. Garmin hereby grants permission to download a single copy of this manual onto a hard drive
or other electronic storage medium to be viewed and to print one copy of this manual or of any revision hereto, provided that such electronic or printed copy of this manual
must contain the complete text of this copyright notice and provided further that any unauthorized commercial distribution of this manual or any revision hereto is strictly
prohibited.
Information in this document is subject to change without notice. Garmin reserves the right to change or improve its products and to make changes in the content without
obligation to notify any person or organization of such changes or improvements. Visit the Garmin Web site (www.garmin.com) for current updates and supplemental information concerning the use and operation of this and other Garmin products.
Garmin®, GPSMAP®, AutoLocate®, TracBack®, BlueChart®, and MapSource® are registered trademarks of Garmin Ltd. or its subsidiaries and may not be used without
the express permission of Garmin.
October 2004
Part Number 190-00321-02 Rev. B
Printed in Taiwan
Preface
Congratulations on choosing one of the most advanced marine navigation systems available! The
Garmin GPSMAP 178/178C Sounder utilizes the proven performance of Garmin GPS and full-featured mapping to create an unsurpassed marine navigation chartplotter.
To get the most out of your new navigation system, take the time to go through this owner’s manual and
learn the operating procedures for your unit. This manual is broken into two parts for your convenience.
Introduction
Preface/Registration/
Software License Agreement
Part One introduces you to the GPSMAP 178/178C Sounder and provides a Getting Started tour so that
you may become more familiar with the unit. This section provides you with a basic knowledge necessary to
use the unit.
Part Two is divided into sections that provide detailed references to the advanced features and operations of the GPSMAP 178/178C Sounder. This allows you to concentrate on a specific topic quickly and look
up detailed information about the GPSMAP 178/178C Sounder.
Software License Agreement
BY USING THE GPSMAP 178/178C, YOU AGREE TO BE BOUND BY THE TERMS AND CONDITIONS
OF THE FOLLOWING SOFTWARE LICENSE AGREEMENT. PLEASE READ THIS AGREEMENT CAREFULLY.
Garmin grants you a limited license to use the software embedded in this device (the “Software”) in
binary executable form in the normal operation of the product. Title, ownership rights and intellectual property rights in and to the Software remain in Garmin.
You acknowledge that the Software is the property of Garmin and is protected under the United States
of America copyright laws and international copyright treaties. You further acknowledge that the structure,
organization and code of the Software are valuable trade secrets of Garmin and that the Software in source
code form remains a valuable trade secret of Garmin. You agree not to decompile, disassemble, modify,
reverse assemble, reverse engineer or reduce to human readable form the Software or any part thereof or
create any derivative works based on the Software. You agree not to export or re-export the Software to any
country in violation of the export control laws of the United States of America.
Product Support Product Registration
Help us better support you by completing our
on-line registration today!
Have the serial number of your GPSMAP 178/178C
handy and connect to our web site (www.garmin.com).
Look for the Product Registration link on the Home
page. Also, be sure to record your serial number in the
area provided on page iv of this manual.
NOTE: If you have previously registered a Garmin
product purchase, we invite you to re-register using
our NEW on-line system. Many services provided by
our new product registration system are now being
automated and re-registering your purchase ensures
you the best possible support from Garmin.
i
FCC Compliance
Introduction
FCC Compliance
The GPSMAP 178/178C Sounder complies with Part 15 of the FCC interference limits for Class B digital
devices FOR HOME OR OFFICE USE. These limits are designed to provide more reasonable protection
against harmful interference in a residential installation, and are more stringent than “outdoor” requirements.
Operation of this device is subject to the following conditions: (1) This device may not cause harmful
interference, and (2) this device must accept any interference received, including interference that may
cause undesired operation.
This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in
accordance with the instructions, may cause harmful interference to radio communications. However,
there is no guarantee that interference will not occur in a particular installation. If this equipment does
cause harmful interference to radio or television reception, which can be determined by turning the
equipment off and on, the user is encouraged to try to correct the interference by one of the following
measures:
• Reorient or relocate the receiving antenna.
• Increase the separation between the equipment and the receiver.
• Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.
• Consult the dealer or an experienced radio/TV technician for help.
The GPS 178/178C Sounder does not contain any user-serviceable parts. Repairs should only be made
by an authorized Garmin service center. Unauthorized repairs or modifications could result in permanent
damage to the equipment, and void your warranty and your authority to operate this device under Part
15 regulations.
ii
The GPS system is operated by the United States government, which is solely responsible for its
accuracy and maintenance. The system is subject to changes which could affect the accuracy and performance of all GPS equipment. Although the Garmin GPSMAP 178/178C is a precision electronic NAVigation AID (NAVAID), any NAVAID can be misused or misinterpreted and, therefore, become unsafe.
Introduction
Warnings and Cautions
The electronic chart is an aid to navigation and is designed to facilitate the use of authorized government charts, not replace them. Only official government charts and notices to mariners contain all
information needed for safe navigation – and, as always, the user is responsible for their prudent use.
Use the GPSMAP 178/178C at your own risk. To reduce the risk of unsafe operation, carefully
review and understand all aspects of this Owner’s Manual—and thoroughly practice operation using the
simulator mode prior to actual use. When in actual use, carefully compare indications from the GPSMAP
178/178C to all available navigation sources, including the information from other NAVAIDs, visual
sightings, charts, etc. For safety, always resolve any discrepancies before continuing navigation.
CAUTION: IT IS THE USER’S RESPONSIBILITY TO USE THIS PRODUCT PRUDENTLY. THIS
PRODUCT IS INTENDED TO BE USED ONLY AS A NAVIGATIONAL AID AND MUST NOT BE USED
FOR ANY PURPOSE REQUIRING PRECISE MEASUREMENT OF DIRECTION, DISTANCE, LOCATION, OR TOPOGRAPHY.

MAP DATA INFORMATION: One of the goals of Garmin is to provide customers with the most complete and accurate cartography that is available to us at a reasonable cost. We use a combination of governmental and private data sources, which we identify (as required) in product literature and copyright
messages displayed to the consumer. Virtually all data sources contain inaccurate or incomplete data to
some degree. This is particularly true outside the United States, where complete and accurate digital data
is either not available or prohibitively expensive.
WARNING: This product, its packaging, and its components contain chemicals known to the State
of California to cause cancer, birth defects, or reproductive harm. This Notice is being provided in accordance with California’s Proposition 65. If you have any questions or would like additional information,
please refer to our web site at http://www.garmin.com/prop65..
iii
LIMITED WARRANTY
Introduction
Warranty and
Serial Number
Serial Number
Use this area to record the serial number (8-digit number
located on the back of the unit) in case it is lost, stolen, or
needs service. Be sure to keep your original sales receipt in a
safe place or attach a photocopy inside the manual.
Serial Number:
*
*

The Garmin GPSMAP 178/178C has no user-serviceable
parts. and is fastened shut with screws. Any attempt to
open the case to change or modify the unit in any way voids
your warranty and may result in permanent damage to the
equipment.
iv
This Garmin product is warranted to be free from defects in materials or workmanship for one year from the
date of purchase. Within this period, Garmin will at its sole option repair or replace any components that fail in
normal use. Such repairs or replacement will be made at no charge to the customer for parts or labor, provided that
the customer shall be responsible for any transportation cost. This warranty does not cover failures due to abuse,
misuse, accident or unauthorized alteration or repairs.
THE WARRANTIES AND REMEDIES CONTAINED HEREIN ARE EXCLUSIVE AND IN LIEU OF ALL OTHER
WARRANTIES EXPRESS OR IMPLIED OR STATUTORY, INCLUDING ANY LIABILITY ARISING UNDER ANY
WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, STATUTORY OR OTHERWISE. THIS WARRANTY GIVES YOU SPECIFIC LEGAL Rights, WHICH MAY VARY FROM STATE TO STATE. IN
NO EVENT SHALL GARMIN BE LIABLE FOR ANY INCIDENTAL, SPECIAL, INDIRECT OR CONSEQUENTIAL
DAMAGES, WHETHER RESULTING FROM THE USE, MISUSE, OR INABILITY TO USE THIS PRODUCT OR
FROM DEFECTS IN THE PRODUCT. Some states do not allow the exclusion of incidental or consequential damages, so the above limitations may not apply to you.
Garmin retains the exclusive right to repair or replace the unit or software or offer a full refund of the purchase
price at its sole discretion. SUCH REMEDY SHALL BE YOUR SOLE AND EXCLUSIVE REMEDY FOR ANY BREACH
OF WARRANTY.
Products sold through online auctions are not eligible for rebates or other special offers from Garmin. Online
auction confirmations are not accepted for warranty verification. To obtain warranty service, an original or copy of
the sales receipt from the original retailer is required. Garmin will not replace missing components from any package
purchased through an online auction. To obtain warranty service, contact your local Garmin authorized dealer or
call Garmin Product Support for shipping instructions and an RMA tracking number. The unit should be securely
packed with the tracking number clearly written on the outside of the package. The unit should then be sent, freight
charges prepaid, to any Garmin warranty service station. A copy of the original sales receipt is required as the proof
of purchase for warranty repairs.
Garmin International, Inc.
1200 E 151st Street, Olathe, Kansas 66062 U.S.A.
Tel. 913/397.8200
Fax. 913/397.8282
Garmin (Europe) Ltd.
Unit 5, The Quadrangle, Abbey Park Industrial Estate,
Romsey, SO51 9DL U.K.
Tel. 44/0870.8501241 Fax 44/0870.8501251
The Garmin GPSMAP 178/178C has no user-serviceable parts. Should you ever encounter a problem with your
unit, please take it to an authorized Garmin dealer for repairs.
The Garmin GPSMAP 178/178C is fastened shut with screws. Any attempt to open the case to change or modify
the unit in any way will void your warranty and may result in permanent damage to the equipment.
Designed for detailed electronic charting capability, the Garmin GPSMAP 178/178C Sounder is a
powerful navigation device that can give you the information you need:
Precision Performance
• (178) 10 level grayscale FSTN display with backlighting
• (178C) High-contrast, 256-color LCD screen with backlighting
• 12-channel parallel receiver tracks and uses up to 12 satellites for fast, accurate positioning
• WAAS Capable — receive signals from the additional set of WAAS (Wide Area Augmentation
System) satellites to give you better accuracy
• Differential-Ready — just add an optional Garmin beacon receiver for better than 5-meter accuracy
• Fully gasketed, high-impact plastic alloy case, waterproof to IEC 529 IPX7
Introduction
Capabilities
Advanced Navigating and Plotting
• 3000 alphanumeric waypoints with selectable icons and comments
• Built-in Worldwide marine basemap to 20 miles includes detailed ocean, river and lake coastlines, cities, interstates, US state highways, and local thoroughfares
• 50 reversible routes with up to 50 waypoints each
• Uploadable maps using Garmin’s MapSource™ PC products and BlueChart™ Data Cards
• Coordinates: Lat/Lon, UTM/UPS, Loran TD, plus over 20 grids, including Maidenhead
• TracBack route feature which allows you to quickly retrace your track log to a starting position
• Built-in simulator mode
• Built-in tide information from over 3,000 tide stations around the USA coastline, Alaska, Hawaii,
western Canada and several Caribbean Islands
Superior Fishfinding Ability
• Whiteline feature provides a clear image of both bottom hardness and structure
• See-Thru® technology helps separate fish returns from thermoclines and structure
• Multiple zoom levels with a moving view window
• Underwater waypoint marking
• Map/Sonar split screen combines navigation and fishfinding information
• Fish and depth alarms
v
Introduction
Packing List

GPSMAP 178/178C Sounder
Standard and Optional Transducers
Unit part numbers 010-00340-00 and 010-00340-01
include a single-frequency 200kHz, plastic, depth and temp,
transom mount transducer.
Unit part numbers 010-00340-02 and 010-00340-03
include a dual-frequency 200/50kHz,, plastic, depth and
temp, transom mount transducer.
Unit part numbers 010-00340-04 and 010-00340-05 do
not include a transducer.
For a complete list of optional transducers, contact your
Garmin Dealer or Garmin direct.
For the most recent list of available accessories for
your GPS unit, current user manuals and software
updates, visit our web site at www.garmin.com.
vi
Before installing and getting started with your unit, please check to see that your package includes
the following items. If any parts are missing, please contact your Garmin dealer immediately.
Standard Package:
• GPSMAP 178/178C Sounder Unit
• GA 29 Remote External Antenna and 30’ cable*
• Internal Antenna**
• Single-Knob Tilt & Swivel Bracket
• Power/Data Cable
• Owner’s Manual
• Quick Reference Card
• Protective Cover
* Not included with part numbers 010-00340-01, 010-00340-03, or 010-003410-05 with internal antenna.
** Not included with part numbers 010-00340-00, 010-00340-02, or 010-003410-04 with remote antenna.
Optional Accessories:
• US A/C PC Adapter
• EURO A/C PC Adapter
• Cigarette Lighter Adapter
• BlueChart Marine Data Cards, MapSource CDs, USB Data Card Programmer and Data Cards
• USB Data Card Programmer
• GBR 21 Beacon Receiver for differential corrections
• Transducers/Temperature Sensors/Water Speed Sensors/Extension Cables
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i
Section Two: Reference . . . . . . . . . . . . . . . . 22-91
Preface/Registration . . . . . . . . . . . . . . . . . . . . . . i
Software License Agreement . . . . . . . . . . . . . . . i
FCC Compliance. . . . . . . . . . . . . . . . . . . . . . . .ii
Warnings and Cautions . . . . . . . . . . . . . . . . . . iii
Warranty and Serial Number. . . . . . . . . . . . . . iv
Capabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . v
Packing List. . . . . . . . . . . . . . . . . . . . . . . . . . . vi
Table of Contents . . . . . . . . . . . . . . . . . . . . . . vii
“How To” Index. . . . . . . . . . . . . . . . . . . . . . . viii
Map Page. . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Cursor . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Zooming . . . . . . . . . . . . . . . . . . . . . . . . . .24
Map Page Options . . . . . . . . . . . . . . . . . . .25
Map/Sonar Split Page. . . . . . . . . . . . . . . . . . . .32
Sonar Page. . . . . . . . . . . . . . . . . . . . . . . . . . . .33
Adjustment Menu . . . . . . . . . . . . . . . . . . .34
Sonar Page Options . . . . . . . . . . . . . . . . . .36
Sonar Tab Options. . . . . . . . . . . . . . . . . . .39
Compass Page . . . . . . . . . . . . . . . . . . . . . . . . .41
Highway Page . . . . . . . . . . . . . . . . . . . . . . . . .42
Highway Page Options . . . . . . . . . . . . . . .43
Waypoints . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
Creating. . . . . . . . . . . . . . . . . . . . . . . . . . .44
Reviewing . . . . . . . . . . . . . . . . . . . . . . . . .48
Editing . . . . . . . . . . . . . . . . . . . . . . . . . . .48
Lists. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
Going to a Destination. . . . . . . . . . . . . . . . . . .53
TracBack Navigation . . . . . . . . . . . . . . . . . . . .54
MOB: Man OverBoard. . . . . . . . . . . . . . . . . . .56
Routes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57
Creating. . . . . . . . . . . . . . . . . . . . . . . . . . .57
Following . . . . . . . . . . . . . . . . . . . . . . . . .58
List Page . . . . . . . . . . . . . . . . . . . . . . . . . .59
Review. . . . . . . . . . . . . . . . . . . . . . . . . . . .60
Editing . . . . . . . . . . . . . . . . . . . . . . . . . . .61
Active Route Page . . . . . . . . . . . . . . . . . . . . . .64
Find Key . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65
Find Options . . . . . . . . . . . . . . . . . . . . . . .66
Section One: Getting Started . . . . . . . . . . . . . 1-21
Keypad Usage . . . . . . . . . . . . . . . . . . . . . . . . . .1
Selecting Options . . . . . . . . . . . . . . . . . . . . . . .2
Entering Data . . . . . . . . . . . . . . . . . . . . . . . . . .3
Initializing the Receiver/Power On . . . . . . . . . .4
Tour/Backlighting . . . . . . . . . . . . . . . . . . . . . . .6
Simulator Mode. . . . . . . . . . . . . . . . . . . . . . . . .7
Main Pages/Map Page . . . . . . . . . . . . . . . . . . . .8
Map Cursor . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Marking Waypoints . . . . . . . . . . . . . . . . . . . . .10
Using the NAV Key . . . . . . . . . . . . . . . . . . . . .11
Simulated Tour . . . . . . . . . . . . . . . . . . . . . . . .12
Reviewing/CreatingMap Waypoints . . . . . .13
Map/Sonar Split Page. . . . . . . . . . . . . . . . .14
Sonar Page. . . . . . . . . . . . . . . . . . . . . . . . .14
Compass Page . . . . . . . . . . . . . . . . . . . . . .16
Highway Page . . . . . . . . . . . . . . . . . . . . . .17
Changing Data Fields/Active Route Page . .19
Main Menu Page/Deleting Waypoints . . . .20
Powering Off Unit . . . . . . . . . . . . . . . . . . . . . .21
Introduction
Table of Contents
Main Menu Page . . . . . . . . . . . . . . . . . . . . . . .67
GPS Tab. . . . . . . . . . . . . . . . . . . . . . . . . . .68
Tide Tab . . . . . . . . . . . . . . . . . . . . . . . . . .73
Trip Tab . . . . . . . . . . . . . . . . . . . . . . . . . . .74
Celestial Tab . . . . . . . . . . . . . . . . . . . . . . .74
Track Tab. . . . . . . . . . . . . . . . . . . . . . . . . .75
DSC Tab . . . . . . . . . . . . . . . . . . . . . . . . . .77
Card Tabs . . . . . . . . . . . . . . . . . . . . . . . . .82
Temp Tab. . . . . . . . . . . . . . . . . . . . . . . . . .83
Setup Tab . . . . . . . . . . . . . . . . . . . . . . . . .83
Comm Tab. . . . . . . . . . . . . . . . . . . . . . . . .86
Alarm Tab . . . . . . . . . . . . . . . . . . . . . . . . .90
Appendix A: Installation . . . . . . . . . . . . . . . . .92
Appendix B: LORAN TD . . . . . . . . . . . . . . . . .102
Appendix C: Map Datums. . . . . . . . . . . . . . .104
Appendix D: Messages . . . . . . . . . . . . . . . . .106
Appendix E: Navigation Terms . . . . . . . . . . .108
Appendix F: Time Offsets . . . . . . . . . . . . . . .110
Appendix G: Understanding Sonar . . . . . . . .111
Appendix H: Specifications/Unit Care. . . . . .116
Appendix I: Index . . . . . . . . . . . . . . . . . . . . .118
vii
Introduction
“How To” Index

The list to the right is provided to help you quickly find
some of the more important procedures you may use on
your new GPSMAP 178/178C.
viii
TO DO THIS:
SEE PAGE(S):
Turn the unit on or off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Adjust screen backlighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Enter data and select options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Learn how to operate the unit’s function keys . . . . . . . . . . . . . . . . . . . . . . . . . 1
Mark your present location as a waypoint . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Go to a destination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Create and use a route . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Pan using the map arrow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Zoom in or out on the Map Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Reconfigure the Map Page display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Adjust Sonar settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Reconfigure the Sonar Page display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Access the Main Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Change units of measure (statute, nautical, metric) . . . . . . . . . . . . . . . . . . . 85
Change the displayed time (zone) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
View tide information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
View celestial information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Set Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Use the Find function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
View a unit message . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
(ZOOM) OUT Key
The OUT key adjusts the map scale to display a larger area with less detail. (Zooms out)
Getting Started
(ZOOM) IN Key
The IN key adjusts the map scale to display a smaller area with more detail. (Zooms in)
Keypad Usage
PAGE Key
The PAGE key selects the main pages in sequence and returns display from a submenu page.
OUT
QUIT Key
The QUIT key returns the display to the previous page and, when entering data, it restores the previous value
(cancels data entry).
PAGE
IN
ARROW KEYPAD
The ARROW KEYPAD is used to select (Highlight) menu options and enter data. It also controls cursor movement
on the Map Page.
QUIT
ENTER/MARK Key
The ENTER/MARK key selects a highlighted menu option. When entering data, it allows you to initiate entry, and
then to accept the selected value(s). It also marks the current location as a waypoint when pressed and held for more
than one second.
ENTER
MARK
Arrow Keypad
MENU Key
The MENU key displays a menu of available options for the current page. Press twice (or press and hold for more
than one second) to display the Main Menu.
MENU
FIND Key
The FIND key activates the find function to search for nearby items and user waypoints.
POWER/ BACKLIGHT Key
The POWER/ BACKLIGHT key turns on/off the unit and and adjusts the display illumination/contrast. Multiple
presses toggle the unit’s backlight between maximum, user-set, and minimum brightness levels.
NAV
MOB
NAV/ MOB Key
The NAV key displays the Go To and Follow navigation menu. MOB (Man Over Board) actives the Man OverBoard
navigation feature when pressed and held for more than one second.
FIND
Power Key
Always press and release a key to perform its primary function. Press, hold for more than one second, then release the
ENTER/MARK , NAV/MOB, and MENU keys to activate
their secondary function.
1
Getting Started
Selecting Options
The GPSMAP 178/178C Sounder’s advanced keypad system is designed to allow for fast, convenient
selection of navigation options and data entry. The Getting Started Tour introduces you to the keypad
and provides a ‘hands-on’ lesson in using the GPSMAP 178/178C Sounder. We strongly encourage you
to follow the Getting Started tour before using your unit for actual navigation. The GPSMAP 178/178C
Sounder Quick Reference Guide contains helpful tips on using the unit and performing various navigation tasks.
Selecting Options and Entering Data
You can select and activate options and enter data to customize the GPSMAP 178/178C Sounder to
fit your requirements. You can use the ENTER/MARK key and ARROW KEYPAD to select options,
enter names and numbers in data fields, and activate your selections.
Options Menu with
highlighted option.
Use the ARROW
KEYPAD to highlight
the next option. Press
ENTER/MARK to
activate.
To select and activate an optional feature:
1. With any page displayed, press the MENU key to pop-up the options menu. The options menu
displays a list of optional features which are specific for that particular page. To select any feature on
the list of options requires movement of the cursor, which is identified as “highlighting”, selecting or
choosing an item in a list or a field (box) on a page.
2. Use the ARROW KEYPAD to move the cursor (highlight) up and down a list or up, down, and sideways on menus.
3. Once you have moved to the desired selection, press the ENTER key to either activate the feature or
the MENU key to pop-up a sub-menu or list of yet more feature options. Repeat this process to select
an option from the list or press the QUIT key to return to the previous setting.
The QUIT key moves backwards through these steps or back to the main page you started on.
To select and activate a function button:
Pop-up list of options for a highlighted field.
2
1. When moving about a page with function buttons, like the ‘New Map Waypoint’ Page, you observe
functions such as ‘Delete’, ‘Show Map’, and ’OK’. To activate the function, highlight the desired
button and press the ENTER key.
Naming a waypoint or placing any sort of data that has not been predefined requires the use of both
the ARROW KEYPAD and the ENTER/MARK key.
To enter a name or number in a data field:
1. Once you have accessed a page with programmable data fields (e.g. ‘ Waypoint Edit’) you can use the
ARROW KEYPAD to move the cursor (highlight) to fields on the page. Use the UP/DOWN arrows to
move up or down and the LEFT/RIGHT arrows to move sideways.
2. Pressing the ENTER key with the field highlighted begins the process for entering data in the form of
alphanumeric characters.
3. Use the ARROW KEYPAD UP/DOWN arrows to cycle through numbers 0 to 9, plus/minus symbols,
blank space, and the alphabet. Pressing and releasing the keypad moves you character by character
through the list. Pressing and holding the keypad moves you rapidly through the list.
Getting Started
Entering Data
Pressing UP or DOWN
on the ARROW KEYPAD
changes numbers and
letters.
4. Use the ARROW KEYPAD LEFT/RIGHT arrows to move to the next character on the line or backwards to edit characters. If there are more than two lines of data, keep pressing to the RIGHT to drop
down to the next line.
5. When data entry is completed press ENTER to accept data, then move to the next programmable
field. Not all data fields are programmable, such as the date and time. When moving about a page
with these fields, the cursor skips over them.
The indicated fields and buttons can
be programmed or activated.
The waypoint can be renamed.
Pressing LEFT or RIGHT
on the ARROW KEYPAD
moves the cursor along the
line or to the next line.
Data Entry Field
A depth can be entered.
A waypoint symbol can be selected
from a list of symbols.
A comment can be added.
A water temperature can be
entered.
Non-programable
data fields
Option buttons can be activated.
The coordinates can be changed.
3
Getting Started
Initializing the Receiver/
Power On
Initializing the Receiver
The first time you power up your GPSMAP 178/178C Sounder, the receiver must be given an
opportunity to collect satellite data and establish its present position. To ensure proper initialization, the
GPSMAP 178/178C Sounder is shipped from the factory in AutoLocate mode, which allows the receiver
to “find itself” anywhere in the world. To speed up the initialization process, we recommend using the
graphic initialization process described on the next page, which usually provides a position fix within a
few minutes.
Before you initialize, make sure the GPSMAP 178/178C Sounder unit and antenna have been correctly installed on your vessel according to the instructions in Appendix A. The antenna needs to be in a
location with a clear and unobstructed view of the sky to receive satellite signals.
To turn on the GPSMAP 178/178C Sounder:
1. Press and hold the POWER key until the power tone sounds and the display comes on, then release
the POWER key.
An Introduction page appears, asking you to read and acknowledge important information regarding
the proper use of the unit.
GPSMAP 178/178C Sounder Warning Screen
4
To acknowledge the introduction:
1. After reading the introduction page, press the ENTER/MARK key if you agree.
To graphically initialize the GPSMAP 178/178C Sounder:
1. Press the MENU key twice for the Main Menu. Press Up or Down on the ARROW KEYPAD until the
‘GPS’ tab is highlighted, then press the MENU key once.
2. Using the ARROW KEYPAD, highlight ‘Initialize Position’ and press ENTER to initialize the receiver
from the map. The Initialize Position Page appears, prompting you to select your
approximate location with the map cursor.
Getting Started
Initializing the Receiver
3. Use the ARROW KEYPAD to move the map cursor and point to your approximate location within
200 miles. If you have difficulty identifying your position, press and release the IN key to see the next
lower map scale.
4. Once you have determined your approximate location on the map, press the ENTER key.

NOTE: This does not “calibrate” the unit in any way, but rather helps to speed up the
initial satellite acquisition. If the unit displays “Ready (2D) or (3D )” during this
process, it is not necessary to initialize the unit.
The GPS Information Page appears as the receiver begins acquiring satellites for your region and
should acquire a fix within a few minutes. When viewing the ‘GPS’ tab on the Main Menu, a signal
strength bar for each satellite in view appears on the bottom of the page, with the appropriate satellite
number under each bar. The progress of satellite acquisition is shown in three stages:
• No signal strength bars— the receiver is looking for the satellites indicated.
• Hollow signal strength bars— the receiver has found the indicated satellites and is collecting data.
• Solid signal strength bars— the receiver has collected the necessary data and the satellites are ready
for use.
Once the receiver has collected information from at least three satellites, the top of the screen displays either “Ready (2D or 3D)”, and the GPSMAP 178/178C Sounder is ready for use.
Point to your approximate location and press ENTER/MARK.
A satellite’s strength bars turns
green when it’s ready for use.
5
Getting Started
Tour/Backlighting
GPSMAP 178/178C Sounder Getting Started Tour
The Garmin GPSMAP 178/178C Sounder is a powerful electronic navigation system that provides
detailed map coverage and convenient control of many advanced features right from the screen display.
This tour is designed to take you through the basic pages and functions of the system using the simulator
mode. Once you’re familiar with the main pages and functions of the unit, refer to the reference section
for instructions on performing specific tasks and functions.
The Getting Started Tour assumes that the receiver has been properly installed and initialized, and
you have not changed any of the default unit settings. If you have changed any settings (position
formats, units of measure, etc.), the descriptions and pictures in the tour may not match your
configuration.
To turn the GPSMAP 178/178C on:
A full-screen GPS Information pop-up page is displayed
after you press the ENTER key to acknowledge the
Warning Page. The pop-up page goes away after the unit
gets a position fix or you press either ENTER or QUIT.
1. Press and hold the POWER key until the power tone sounds, then release the POWER key. The Warning Page appears while the unit conducts a self-test.
2. Once the self-test is complete, press the ENTER/MARK key to agree and acknowledge the warning.
The GPS Information Page appears as the receiver begins acquiring satellites. From this or any other
page, you may also adjust the screen backlighting.
The GPSMAP 178/178C’s adjustable screen backlighting is controlled with the POWER key. The
backlight can cycle through minimum, user-defined, and maximum backlight levels by repeatedly pressing the POWER key.
To adjust the backlighting and contrast:
1. Press POWER and the Light/Contrast window appears.
Use the ARROW KEYPAD to move the backlighting slider
UP for brighter or DOWN for dimmer backlighting. Press
LEF or RIGHT to adjust the display contrast.
6
2. Press POWER again and the user-defined level of backlighting activates. You may adjust this level by
pressing UP or DOWN on the ARROW KEYPAD. If you press POWER one more time, the backlighting is at the minimum setting. Press LEFT (brighter) or RIGHT (darker) to adjust the contrast.
3. Press ENTER or QUIT when done.
Each page of the GPSMAP 178/178C Sounder’s system also features an options page, which gives
you access to other functions and features that relate to the specific page you are viewing. To get a feel for
how the option pages work, let’s put the GPSMAP 178/178C Sounder into simulator mode.
To activate the simulator mode:
Getting Started
Simulator Mode
1. Press the MENU key twice for the Main Menu. Press Up or Down on the ARROW KEYPAD until the
‘GPS’ tab is highlighted, then press the MENU key once.
2. Use the UP or DOWN arrow of the ARROW KEYPAD to highlight the ‘Start Simulator’ option and
press ENTER. Choose ‘No’ to the retail demonstration and press the ENTER key.
3. Press the ENTER key to confirm the ‘Running Simulator’ message that appears at the bottom of the
display. ‘Simulating’ appears at the top of the Main pages.
While in Simulator mode, a ‘Running Simulator’ message appears after 2 minutes of inactivity. Now
you’re ready to continue the rest of the simulated tour. Keep in mind that the GPSMAP 178/178C
Sounder does not track satellites in simulator mode, and this mode should never be used for
actual navigation. All the waypoint and route planning done in simulator mode is still retained in
memory for future use.
A “Running Simulator” message
appears after 2 minutes of
inactivity.
7
Getting Started
Main Pages/
Map Page
Main Pages
The Map Page is one of six main pages used in the GPSMAP 178/178C Sounder’s system. The six
main pages are the Map Page, Map/Sonar Split Page, Sonar Page, Compass Page, Highway Page, and
Active Route Page. All pages are linked together in a simple chain, which allows you to scroll through the
pages in either direction using the PAGE and QUIT keys.
Map Page
Map/Sonar Split Page
PAGE
Sonar Page
Compass Page
Highway Page
Active Route Page
QUIT
Map Page
The GPSMAP 178/178C Sounder’s Map Page combines digital chartplotting with a user-selectable
display of navigation data and a built-in worldwide database. It is also the page you use most to create
and edit waypoints and routes. Before we take off on our practice route, let’s take a brief look at its various features and displays.
The map display shows your “boat” as a triangle marker on an electronically generated chart.
Geographic names, roads, markers and buoys that are provided by the optional BlueChart or MapSource
data are also shown. It also displays your track, routes, and nearby waypoints. An on-screen cursor
lets you pan to other map areas, determine the range and bearing to a position, and perform various
waypoint and route functions.
The data window, located at the top of the page, provides a user-selectable display of various navigation data, including speed over ground, distance to the next navigation point, compass ribbon, and current position coordinates. The current map scale setting is located at the bottom right of the page.
8
Using the Map Cursor
Working from the Map Page is a simple process that centers around the use of the cursor. Controlled
by the ARROW KEYPAD, the cursor is an important tool that can be used to pan to other map locations,
mark and edit waypoints and routes, and review position data of on-screen map items and waypoints.
Getting Started
Map Cursor
To get a feel for using the Map Page and using the cursor, try the following exercise:
1. Use the IN/OUT keys to set the map scale to the 50 nm setting. Your boat should be near the center
of the map, at the receiver’s last known position. (If your boat isn’t where it should be, make sure that
you have initialized the receiver and acquired a position as described on pages 4-5.)
2. Use the ARROW KEYPAD to move the cursor. Notice how another data field appears, showing the
bearing and distance from your boat to the cursor, along with the latitude/longitude of the cursor.
3. Press the QUIT key to remove the cursor and re-center your boat on the map display.
As you become more familiar with the cursor, you’ll see that the map display actively scrolls or ‘pans’,
letting you explore areas around the world and create waypoints and routes. Wherever you move the
cursor, pressing the QUIT key centers the map on your current position.
Now that you’ve seen how the Map Page can be used to monitor your present location, let’s take a
minute to learn how to mark and store your present position as a “waypoint”. Since you’re in simulator mode, the present position displayed is the last position calculated by the receiver, which should be
the spot where you’ve initialized the unit. This also gives you an opportunity to see how the GPSMAP
178/178C Sounder’s keypad and ENTER/MARK key are used for data entry and changing the waypoint
name and symbol.
Current position
Map Scale
Distance/
Bearing
Cursor
Coordinates
Map Cursor
9
Getting Started
Marking Waypoints
To mark your present position:
1. Hold down the ENTER/MARK key until the ‘New Waypoint’ window appears then release the key.
The window shows a default three-digit waypoint name/number (001), symbol (dot), and position.
You can leave the name as the auto-assigned number, but for this exercise, lets change the name to
‘DOCK’.
2. Use the ARROW KEYPAD to highlight the waypoint name field (001) and press ENTER/MARK. You
see that just the first ‘0’ is now highlighted.
3. Press LEFT on the ARROW KEYPAD to clear the name field.
Press ENTER/MARK
after entering the name.
4. Press UP or DOWN on of the ARROW KEYPAD until the letter ‘D’ appears, and then press RIGHT
to go to the next space to the right, then UP or DOWN again until ‘O’ appears. Repeat this until you
have entered the name ‘DOCK’. If you make a mistake and select an incorrect character, simply press
LEFT on the ARROW KEYPAD to backspace the cursor and then UP or DOWN to correct the entry.
(If you accidentally press ENTER/MARK before you are done, simply press ENTER/MARK again and
move the highlight to where you left off.)
5. After you have entered all the letters, press ENTER/MARK to confirm the name.
6. To access the waypoint symbol page, highlight the waypoint symbol field, which is to the left of the
waypoint’s name and press ENTER/MARK. The default symbol is a dot.
7. You see a grid of available waypoint symbols to choose from. Use the ARROW KEYPAD to highlight
the ‘ANCHOR’ symbol.
8. Press ENTER/MARK to confirm the ‘ANCHOR’ symbol.
9. Highlight ‘OK’ at the bottom of the window and press ENTER/MARK again to confirm the ‘OK’
prompt and save the waypoint.
You can choose from a list of useful symbols.
There are two Diver Down waypoint
symbols to select from: the International and
U.S. versions.
10
The waypoint is now stored in memory. Note that waypoints may also be created graphically from
the map display or by manually entering position coordinates. Each of these techniques is described in
the reference section of this manual.
Going to a Destination
GPS is all about marking positions as waypoints and navigating to them using the receiver’s
steering guidance and map displays. We’ve already seen how to use the ENTER/MARK key to store your
present position, so it’s time to move on to the fun part—going to a destination.
Getting Started
Using the NAV Key
The NAV/MOB key, located on the keypad above the QUIT key, is the primary tool used to select a
destination waypoint, TracBack, or a route to navigate. The NAV key can be used in two primary ways:
• Pressing NAV once displays a list of options from which you can select ‘Go To Point’, ‘Follow
Route’, ‘Follow Track’, or ‘Stop Navigation’.
• Highlighting an on-screen waypoint or map item as a destination directly from the Map Page and
pressing NAV allows you to graphically select points to “Go To”.
For our simulated trip, you’re going to select a pre-programmed tour route using the first method.
This also shows how the MENU key is used throughout the GPSMAP 178/178C Sounder system to
provide tab style options and functions. Let’s start by changing the position to where the practice route is
located.
Text entry for simulator position.
To change the GPSMAP 178/178C Sounder position in simulator mode:
1. Press the MENU key twice to display the list of Main Menu tab items.
2. Use the UP or DOWN arrow of the ARROW KEYPAD to highlight the ‘Setup’ tab, then LEFT or RIGHT
to highlight the ‘System’ submenu tab.
3. Highlight ‘Set Position’ in the simulator setup window and press ENTER.
4. From the Initialize Position Page, press the MENU key. You see ‘Enter As Text’ highlighted, then press
ENTER.
5. On the Enter Position window, press ENTER then use the ARROW KEYPAD to enter N34°56.800’,
W076°24.066’ and press ENTER when done, then press QUIT to return to the Map Page.
For future practice, you may skip steps
4 and 5 and point to a location from the
Initialize Position Page.
11
Getting Started
Simulated Tour
To activate the practice route stored in memory for navigation:
1. Press NAV. The option list page appears. (If you were selecting a single waypoint to navigate to rather
than a route, you could highlight the waypoint on the map, press NAV and then press ENTER.)
2. Use the ARROW KEYPAD to highlight the ‘Follow Route’ option. Press ENTER to confirm.
3. The Select Route Page appears, with the ‘GPSMAP TOUR’ route highlighted.
4. Press ENTER then highlight ‘Activate’ and press ENTER again.
To zoom in to a closer map scale:
1. Repeatedly press the IN key until the 3 nm scale displays.
You may also hold the IN or OUT keys down to quickly scroll through the map scales. The Map
Page should now display five waypoints chained together in a simple route, with your boat at the first
route waypoint.
You can also Invert a route to
follow it in reverse.
A data field at the top of the page now displays the speed, distance to the second route waypoint,
and a compass ribbon which shows you which way to go. To get started, let’s enter a speed for our vessel,
which we can do from the Main Menu Page.
To enter a boat speed:
1. Press the MENU key twice to display the Main Menu Page.
2. Use the ARROW KEYPAD to highlight the ‘Setup’ tab, then press RIGHT then DOWN until the field
below the word ‘Speed’ is highlighted on the ‘System’ submenu tab and press ENTER.
3. Use the ARROW KEYPAD to enter a speed of 40 knots.
4. Press ENTER to finish, and PAGE until you return to the Map Page.
The Set Position, Track Control, Track
and Speed fields only show while in
simulator mode.
12
Once a speed has been entered, you’ll notice that the map automatically begins to move slowly, keeping your boat centered on the display. The direction of movement, also called ‘track’, is controlled by the
simulator.
You’ll now have a clearer picture of the route you are navigating. Keep in mind that when you exceed
the usable range of the built-in database or the optional MapSource or BlueChart data in use, the range
field displays ‘overzoom’ to indicate that you should exercise extreme caution using the map data. Press
the ZOOM IN key to zoom into the 2 nm scale. Now that you’ve zoomed in a little closer to your route,
you can pan ahead of your vessel with the cursor to review map items and create on-screen waypoints.
Move the cursor to highlight the ‘TOUR3’ waypoint— just use the ARROW KEYPAD to move the cursor
as close as possible to the waypoint (To move the cursor in small increments, try a series of short key
presses).
Once the cursor is over the TOUR3 waypoint, you’ll notice that the waypoint symbol and name
are highlighted. The data field at the top of the map displays the waypoint name, the range and bearing
from your present position, and the coordinates for the waypoint.
Getting Started
Reviewing/Creating
Map Waypoints
To review the waypoint page for a selected waypoint:
1. With the waypoint highlighted, press ENTER.
2. To return to the Map Page, press ENTER again or press QUIT.
The cursor can also be used to create new waypoints right from the map display.
The waypoint ‘highlights’
when the cursor is moved
over it.
To create a new waypoint using the cursor:
1. Use the ARROW KEYPAD to move the cursor as close as possible to the following position:
N35º 02.914; W 076º 26.152’ (Use the data window to verify the cursor position.)
2. Press and release the ENTER/MARK key to capture the cursor position. Do not hold the button
down, as doing so marks your present position, not the map position.
3. Use the ARROW KEYPAD to highlight the waypoint symbol field to the left of the waypoint name/
number.
4. Press ENTER to access the symbol page.
5. Use the ARROW KEYPAD to select the ‘Shipwreck’ symbol and press ENTER to confirm.
6. Highlight ‘OK’ and press ENTER again to finish.
Waypoint numbering starts with
001 and continually counts up,
even if the waypoint name has
been deleted.
13
Map/Sonar Split Page
Getting Started
The Map/Sonar Split Page combines the Map Page on the left half with the Sonar Page on the right by
default. You may adjust the size of the split (pg 32). Press PAGE key to proceed to the Sonar Page.
Map/Sonar Split &
Sonar Pages
Data Fields
Sonar Page
Adjustment
Menu
Simulated
Fish Arch
Depth
Scale
Bottom
Flasher
Thermocline
Sonar Page
Outer edge
beam returns
Center beam
return
Frequency
mode
Dual frequency returns
14
The Sonar Page is where your GPSMAP 178/178C Sounder becomes a powerful fishfinder. The top
left of the screen contains data fields, while the Adjustment Bar above the data fields allows direct access
to the settings most commonly changed while using the Sonar Page. The middle of the page contains a
right-to-left moving sonar image of the water beneath your boat (Items appear as they pass under your
transducer. Those items on the right side of the screen are closer to you than those on the left.). Along the
right side of the screen is an adjustable scale which reflects the depth of the area being displayed. If the
unit does not detect a transducer attached to the unit, a “Sonar Turned Off” message appears across the
Sonar Page. You may also show a sonar flasher and color bar on the right side.
The sonar display may also be set to show a split screen view of a zoomed portion of the sonar,
bottom lock (display scaled from the bottom up), or a combination of these options (see pg. 34). For
example, you may choose to show dual frequency at a 2X zoom (Dual 2X) on one half and normal range
dual frequency (Dual) returns on the other half. The current display mode is displayed at the bottom of
each sonar display.
(172C) Sonar returns show as red (strongest), then oranges (strong), yellows (medium), greens
(weaker) and blues (weakest). (172) The stronger sonar returns are darker, weaker returns are displayed
in a lighter shade of gray. The ‘Fish Symbols’ option (see page 38) allows you to view the actual sonar
data, a fish symbol, or a combination of both. ‘Fish Symbols’ appear as green (172C), or dark gray (172).
When the unit is set to ‘Dual’ frequency (see page 35), the appearance of the fish symbols (and simulated
fish returns) changes. Fish symbols from the narrower beam (200kHz) are solid (or narrow returns), but
the symbols from the wider beam (50kHz) are hollow (or wide returns). Fish icons are displayed in three
different sizes. Actual fish returns may not always appear as perfect arches, due to the speed, fish orientation, and/or other conditions.
More on understanding the Sonar Page may be found on page 33 and in Appendix G.
Using the Adjustment Menu
The Adjustment Menu allows direct access to the settings and features most commonly used on the
Sonar Page. There are 10 main adjustment options available: Range, Zoom, View/Span, Gain, Target
Level, Whiteline, Frequency, Depth Line, Noise Reject, and Scroll. The currently selected option appears
in the upper left of the display with up and down arrows on either side of the option name.
Getting Started
Sonar Page
To select an adjustment option from the Sonar Page:
1. Press the ARROW KEYPAD LEFT/RIGHT to scroll through the options in the upper left of the display,
then press ENTER to access the desired option’s adjustment window.
OR:
1. Press MENU, highlight ‘Adjustments’ and press ENTER. A list of all options and their current settings
appears, with the selected option highlighted. Press UP/DOWN on the ARROW KEYPAD to select the
desired option and press ENTER to access the adjustment window.
To easily exit any of the adjustment options, press the QUIT key.
To change an Adjustment Menu setting:
1. Select an adjustment option to change using one of the two methods described above. The adjustment window automatically times out and disappear when idle for 20 seconds.
Press MENU, highlight ‘Adjustments’ and press ENTER to see a
list of all options and their current
settings.
2. Press the ARROW KEYPAD UP/DOWN to place the pointer or setting bar at the desired setting,
range or percentage (Off, 1-100%).
3. Press ENTER or QUIT to exit the adjustment window; or press LEFT/RIGHT on the ARROW KEYPAD
to view another adjustment window.
To change a setting back to ‘Normal’ or ‘Auto’:
1. On the adjustment window for the desired option, press MENU.
2. Select the desired setting and press ENTER.
For detailed information on the functions and options of the Sonar Page, see page 33. To learn more
about how sonar works, see Appendix G.
Zoom adjustment options
15
Let’s move on to the GPSMAP 178/178C Sounder’s navigation pages by pressing the PAGE key.
Getting Started
Compass Page
Compass Page
Data
Fields
The Compass Page provides graphic steering guidance to a destination waypoint, with an emphasis
on the bearing to your destination and current direction of travel. The middle of the page features a rotating ‘compass ring’ that shows your course over ground (track) while you’re moving, and a bearing pointer
that indicates the direction of the destination (bearing) relative to the course over ground. The compass
ring and pointer arrow work independently to show—at a glance—the direction of your movement
and the direction to your destination. For instance, if the arrow points up, you are going directly to the
waypoint. If the arrow points any direction other than up, turn toward the arrow until it points up—then
continue in that direction. Bacause the compass rings uses GPS technology, you must be moving in order
for the track to display properly.
Compass
Ring
Current
Destination
Pointer
Arrow
Compass Page
The current speed, distance to the next waypoint, turn angle, and time to the next waypoint display
at the top of the screen. When you are not navigating to a waypoint, the compass shows your direction of
travel as you move, but the arrow does not appear.
The Compass Page allows for precision navigation to one degree of steerage. The default page
displays one row of medium numbers fields. You may customize the Compass Page to display the size
and number of fields along with the type data you wish to see. (See pages 30-31 for changing the types of
data.)
Press the PAGE key to display the Highway Page.
16
Highway Page
Getting Started
The GPSMAP 178/178C Sounder’s Highway Page also provides graphic steering guidance to a destination waypoint, placing greater emphasis on the straight-line desired course and the distance and direction you are off course. As you head toward your destination, the middle of the screen provides visual
guidance to your waypoint on a moving graphic “highway.” Your present position is at the bottom center
of the highway display. The line down the middle of the highway represents your desired course.
As you navigate toward a waypoint, the highway actually moves, indicating the direction you’re off
course. To stay on course, simply steer toward the center of the highway or “keep it on the road”. The
default data fields at the top of the page indicate ‘Speed’ and ‘Distance To Next’ point, along with ‘To
Course’ which shows the bearing to get you back on course and ‘Time To Next’ point. Use the Highway
Page as your primary navigation page (in lieu of the Compass Page) when your main concern is following
a defined course.
Whenever the GPSMAP 178/178C Sounder is in simulator mode, you can also adjust your speed and
course from the Highway Page using the ARROW KEYPAD. As you head toward each waypoint in the
tour route, try adjusting your boat speed and course to get a feel for how the Highway Page works.
Highway Page
Data
Fields
Present
Position
Current
Destination
Zoom
Scale
Desired
Course
Highway Page
To adjust the simulated boat speed/heading from the Highway Page:
1. Press the UP arrow of the ARROW KEYPAD to increase the speed in 10 knot/kph/mph increments.
Press the DOWN arrow to decrease the speed in the same increments. Press the LEFT and RIGHT
arrows of the ARROW KEYPAD to steer the boat (adjust the heading).

NOTE: In simulator mode, you may also change the simulated speed by pressing UP or
DOWN on the ARROW KEYPAD from the Compass Page.
Notice that as you get off course, the highway moves to give you graphic guidance to get back on
course. You can zoom in or out on the Highway display for a smaller or larger view. Five available settings
range from 1X to 16X, with a default setting of 8X. The current scale appears in the bottom right of the
display.
To zoom in or out on the highway display:
Steer towards the center of the highway to get back
on course.
17
1. Press either the IN or OUT key to increase or decrease the zoom scale.
Getting Started
Highway Page
Changing Data Fields
The data fields on the main pages may also be configured to display several different information
categories (see pages 30-31 for the complete list). On the Highway Page, let’s change the ‘TIME TO NEXT’
field to ‘TIME OF DAY’.
To change a data field:
1. Press the MENU key to display the Highway Page options.
2. With ‘Change Numbers’ highlighted, press ENTER.
3. Use the ARROW KEYPAD to highlight ‘TIME TO NEXT’, then press ENTER.
4. On the alphabetical list of options, press UP or DOWN on the ARROW KEYPAD to highlight a selection. Press LEFT or RIGHT to jump through the list a page at a time. The scroll bar on the right side of
the window indicates the current position on the entire list of options. Select ‘TIME OF DAY’ and press
ENTER.
5. Press QUIT when finished.
You may choose from several
different types of data
The layout of the data fields may also be changed to show more fields (with a smaller number size) or
less fields (with a larger number size). This setting is available on all of the Main Pages, except the Active
Route Page.
To set up the page layout:
18
1. Press the MENU key to display the Page options.
Getting Started
2. Highlight ‘Set Up Page Layout’ and press ENTER.
3. The current setting displays, press ENTER to change. Use the ARROW KEYPAD to highlight ‘the
desired setting, then press ENTER.
4. Press QUIT when finished.
Changing Data Fields/
Active Route Page
Active Route Page
Press PAGE to see the last page appearing in the main sequence, which is the Active Route Page.
Whenever you have activated a route or Follow Track, this page lists the names of the route points along
with useful data for each point. As you navigate the route, the information automatically updates to indicate the next point along the route. For more detailed information on the Active Route Page, see page 64.
You may change the size of
the data fields.
Current
waypoint
Active Route Page
19
Getting Started
Main Menu Page/
Deleting Waypoints
Main Menu Page
As you’ve seen, the primary pages provide map, sonar, and navigation information. The tour’s last page
is the Main Menu Page, which allows access to the GPSMAP 178/178C Sounder’s waypoint, route, and
planning functions, as well as various operational and navigation setup features, and celestial and tide data.
The Main Menu is available from any page, and is accessed through the MENU key.
To access the main menu page:
1. Press the MENU key twice (or hold down the MENU key for two seconds.).
Submenu
Tabss
The Main Menu Page lists 16 vertical ‘tabs’ that are divided into categories by function. You can
view a particular menu by simply highlighting the desired tab, which shows any secondary (horizontal)
submenu tabs and options for that tab.
To get a basic feel for how the Main Menu Page works, let’s delete the two waypoints you created
during the simulated tour. This ensures that you have a clean slate once you start navigating in your
home waters.
Main
Menu
Tabs
To delete the practice waypoints:
1. Use the ARROW KEYPAD to highlight the ‘Points’ menu tab. You see a list of stored waypoints
appear to the right of the Main Menu list.
2. Press RIGHT one time on the ARROW KEYPAD to highlight the ‘User’ submenu tab.
Main Menu
3. Press DOWN on the ARROW KEYPAD and highlight waypoint ‘001’ with the shipwreck symbol.
4. You may delete the waypoint by either pressing MENU, then highlighting ‘Delete Waypoint’; or by
pressing ENTER and then highlighting ‘Delete’ from the Waypoint Edit Page.
5. Press ENTER to delete the waypoint, then ENTER again to confirm. Repeat the above steps to delete
the ‘Dock’ waypoint also.
20
Congratulations! You’ve now gone through the basic operation of the Garmin GPSMAP 178/178C
Sounder. Your new digital chartplotter is a powerful tool with many advanced features not covered in the
Getting Started tour. For detailed instructions on using these features or performing a specific task, please
refer to the Quick Reference Guide or the appropriate reference section of this manual. The unit is still in
Simulator mode for practice, but automatically returns to it’s ‘Normal’ operation mode when you shut it
off and turn it back on.
Getting Started
Powering Off Unit
To turn the GPSMAP 178/178C Sounder off:
1. Press and hold the POWER key for about 2 seconds, until the screen is blank.
2. When the screen is blank, release the POWER key.
The next section of the manual describes the pages and functions of the GPSMAP 178/178C Sounder
in detail. If you are unable to locate a specific option or function, please refer to the Index.
21
Map Page
Reference
Map Page
Data Fields
Land
User
Waypoint
Map
Item
Boat Icon
Water
Navaids
Geographic Name
Map Page shown using optional
MapSource data.
22
Map Scale
The GPSMAP 178/178C’s Map Page provides a comprehensive display of electronic cartography,
plotting, and navigational data. When using the unit with the optional BlueChart data or MapSource software, the map display shows your boat on a digital chart, complete with geographic names, map items,
navaids and a host of other chart features. It also plots your track and displays any routes and waypoints
you create. An on-screen cursor lets you pan and scroll to other map areas, determine the distance and
bearing to a position, and perform various route and waypoint functions.
When the cursor is active, an additional data window appears below the data fields to indicate the
position, range and bearing to the cursor or a selected waypoint or map item. The map scale displays at
the bottom right of the page.
The (ZOOM) IN and (ZOOM) OUT keys, combined with the ARROW KEYPAD, let you select
zoom ranges and move the cursor. Two basic map operating modes, position mode and cursor mode,
determine what cartography is shown on the map display. Position mode pans the cartography to keep
the present position marker within the display area, while cursor mode pans the cartography to keep the
cursor within the display area.
The GPSMAP system always powers up in the position mode, with your vessel centered on the map
display. When sufficient map coverage is not available to keep the boat centered, the boat icon moves
toward the edge of the display.
When the ARROW KEYPAD is pressed, the GPSMAP 178/178C enters cursor mode. In cursor
mode:
• The cursor can be moved over the map display using the ARROW KEYPAD.
• Whenever the cursor reaches the edge of the display, the map scrolls forward under the cursor.
Keep in mind that the boat icon moves with the map scrolling and may go off the display screen
(you may not be able to see your present position).
• When the cursor is stationary, a fixed coordinate position appears in the position field. Note that
the distance and bearing changes as the boat’s position changes.
• Whenever you zoom in cursor mode, the cursor is centered on screen.
• To return to position mode, press the QUIT key.

When the cursor reaches the edge of the map, the unit may pause as it loads new map
data.
Reference
Map Page: Cursor
Using the Cursor
The cursor allows you to pan away from your present position and scroll to other map areas around
the world (even outside of your current detail coverage). As you pan past the edge of the current map
display, the screen actively scrolls forward to provide continuous map coverage. You see an hourglass
symbol by the pointer while the unit is busy drawing new map detail.
To move the cursor:
1. Press the ARROW KEYPAD to move the cursor in an up, down, left or right direction.
As you move the cursor, the distance and bearing from your present position to the cursor is
displayed in the data window, along with the cursor’s position coordinates. Keep in mind that when the
cursor is stationary, the distance and bearing from your present position changes as your boat moves.
The cursor may also be used to ‘snap’ to on-screen waypoints and map items, allowing you to review a
selected position directly from the map display.
Move the cursor over an item
on the map to highlight it.
Additional information
tabs.
To select an on-screen waypoint or map item with the cursor:
1. Use the ARROW KEYPAD to move the cursor to the desired waypoint or map item (if there are
several waypoints grouped closely together, zoom in closer for a better view).
2. When a waypoint or map item is selected, it becomes highlighted on screen, with the name and position displayed. Press ENTER to show details of the map item. When using BlueChart or MapSource
data, additional information tabs appears. Use the ARROW KEYPAD to highlight the individual tabs
to display the information and additional options.
Pressing ENTER/MARK
while highlighting a map
item brings up additional
details and options.
Option buttons
23
Reference
To eliminate the cursor and re-center your position on-screen:
1. Press the QUIT key.
The cursor may also be used to create new waypoints directly from the map.
Map Page: Cursor
and Zooming
To create a waypoint with the cursor:
1. Use the ARROW KEYPAD to move the cursor to the desired map position.
2. Press the ENTER/MARK key and the ‘New Map Waypoint’ window appears. If the cursor is on a
map item, you get a new window with details about the item when ENTER/MARK is pressed. Press
ENTER again on the highlighted ‘Create Wpt’ option.
3. Press ENTER to confirm the new waypoint using the default three-digit name and symbol.
Selecting Map Scales
The map display has 28 available range scales from 20 ft. to 800 mi. (5 m to 1200 km). The map
scale is controlled by the IN and OUT keys, with the current scale displayed at the bottom right of the
data window.
Creating New Map Waypoint
To select a map scale:
1. Press the OUT key to zoom out and the IN key to zoom in.

Using Built-In Basemap
Using BlueChart/MapSource Data
Overzoom, no additional data
24
The scale value represents the distance from one end of the scale bar to the other.
The GPSMAP 178/178C’s system has a built-in worldwide database to 20 mi, with more detailed
coverage available through the use of the optional BlueChart or MapSource data. The GPSMAP 178/178C
displays cartography as long as there is chart information available for the range you’ve selected. Map
coverage conforms to the following conditions:
• When the selected zoom range is covered by either the internal database, BlueChart, or
MapSource data, cartography is displayed.
• When the selected zoom range is covered by both the internal database and BlueChart/
MapSource data, cartography is displayed using the data with the best resolution.
• When the selected zoom range exceeds the resolution of the data in use, overzoom cartography is
displayed and an ‘overzoom’ warning appears below the scale field.
Map Page Options
Many features of the GPSMAP 178/178C are menu driven. Each of the main pages have an options
menu, allowing you to custom tailor the corresponding page to your preferences and/or select special features that specifically relate to that page. The data window, located at the top of the main pages provides
a user-selectable layout of various types of useful data. Each data field may be configured to display any
one of several data options. The data window layout may also be changed to display additional data fields
and change the actual size of the data displayed.
Reference
Map Page: Options
The GPSMAP 178/178C’s Map Page provides access to functions and features relating to the Map
Page and the layout options.
To display the Map Page options:
1. Press MENU.
To select a menu option:
1. Use the ARROW KEYPAD to highlight the desired option and press ENTER.
The available options are Full Screen Map/Show Data, Measure Distance, Set Up Map, Set Up Page
Layout, Change Numbers, and Turn Declutter On/Off. Following are details on using each of these
options.
• Full Screen Map/Show Data — toggles between a Map Page without or with data fields on the
map display. The unit defaults back to ‘Show Data” the next time it is powered on.
Map Page Options
To maximize the map/show data fields:
1. Highlight the ‘Full Screen Map’ option and press ENTER. The Map Page is now maximized with no
data fields.
2. To show the data fields again, press MENU, highlight ‘Show Data’ and press ENTER.
25
• Measure Distance— allows you to measure the bearing and distance between any two points on
the map display.
Reference
Map Page Options
Cursor
Coordinates
Distance and
Bearing
Map Cursor
Full screen map shown
To measure the Bearing/distance between two points:
1. Highlight the ‘Measure Distance’ option and press ENTER. An on-screen pointer appears on the map
display at your present position with ‘ENT REF’ below it.
2. Move the cursor to the desired reference point (the point that you want to measure from) and press
ENTER.
3. Move the cursor to the point that you want to measure to. The bearing and distance from the reference point and cursor coordinates is displayed in the data window at the top of the display. Press the
QUIT key to finish.
• Set Up Map— allows you to configure the map display to your preferences, including map detail,
map orientation, automatic zoom, and various map items and points. The map set up option uses a ‘file
tab’ feature, making it easier to organize the various settings for ease of use. The following table lists the
file tabs and the settings available under each tab:
General
Detail, Orientation, AutoZoom, Color Mode
Source
Basemap, Data Card Maps
Waypoints Waypoints, Active Route
Points Spot Soundings, Tide Stations, Services
Navaids
Symbol Set, Symbol Size, Text Size, Light Sectors
Nav Line Heading Line, Bearing Line, Course Line
Track
Saved Tracks, Track Log
Other
Accuracy Circle, Lat/Lon Grid, Map Outlines
To change a map setup feature:
1. From the Map Page menu, highlight ‘Set Up Map’ and press ENTER.
Main Menu—
Map Configuration Tab
26
2. Move LEFT or RIGHT on the ARROW KEYPAD to highlight the desired tab, then UP or DOWN on the
ARROW KEYPAD to move the highlight to the setting you want to change and press ENTER.
3. Move UP or DOWN on the ARROW KEYPAD to highlight to the desired setting and press ENTER.
To exit, press QUIT.
General Tab
Detail— Most, More, Normal, Less, Least: controls how much map detail displays. Those features
which have a specified scale or turned “Off” are unaffected by this setting.
Orientation— North Up— fixes the top of the map display to a north heading; Track Up Below—
fixes the top of the map display to the current track heading and centers your position on the
lower portion of the screen. Set to ‘Off; for constant Track Up. The numeric value is the range
the unit switches to North Up when zooming out. Course Up— fixes the map so the direction of
navigation is always “up” and turns the navigation leg line vertical on the screen.
AutoZoom— On/Off: when “On” the map automatically adjusts the map scale to a lower scale as
you approach you destination point.
Color Mode — (178C) For Sun, For Dark: (178) Water Mode, Land Mode
Source Tab
Basemap— On/Off: turns the built in base map on or off.
Data Card Maps— On/Off: turns all optional BlueChart/MapSource data loaded on the data card
on or off. The ‘Data Card Maps’ option box shows a list of the optional BlueChart/MapSource
data loaded on the data card. Each area is described by name and may be deselected if you do not
wish to display the data on the Map Page.
Reference
Map Page Options
General Tab
Source Tab
To display the Map Information Page:
1. Highlight the ‘Data Card Maps’ option box and press ENTER.
2. Use the ARROW KEYPAD to scroll through the list of maps.
3. To select/deselect a map family, highlight the check box to the left of the name and press ENTER to
select/deselect the map. The map is selected and is displayed on the Map Page when an “” appears
in the box adjacent to that map. You may also press MENU and choose to ‘Show All’ or ‘Show None’
and press ENTER.
4. To display detailed information/notes for each area or to turn individual maps in the family on/off,
highlight the family name and press ENTER. To view the notes for that area, choose ‘Show Notes’.
To scroll through the notes, you may either highlight the notes, press ENTER and use the ARROW
KEYPAD to scroll UP, DOWN, LEFT and RIGHT or press MENU and choose the desired scroll option.
‘Data Card
Maps’ Map
Information
Page
27
Reference
Map Page: Options
Waypoints Tab— Waypoints/Active Route
Text— None, Small, Medium, and Large: controls the screen size of the name.
Zoom— Auto, Off, 20 ft.-800 mi.: sets the maximum scale at which the feature should appear on
the screen. Some types of data only shows up to certain zoom scales.
Points Tab— Spot Soundings/Tide Stations/Services
Text— None (except Spot Snd.), Small, Medium, and Large: controls the screen size of the name.
Zoom— Auto, Off, 20 ft.-800 mi.: sets the maximum scale at which the feature should appear on
the screen. Some types of data only shows up to certain zoom scales.
Navaids Tab—
Waypoints
Tab
Points Tab
Symbol Set— Auto, GARMIN, NOAA, International: controls the desired navaid symbol set.
Auto - BlueChart maps are drawn using symbols similar to the NOAA/NIMA standard. NonBlueChart maps are drawn using traditional Garmin symbols.
GARMIN - All maps are drawn using traditional Garmin symbols.
NOAA - All maps are drawn using a symbol set similar to NOAA/NIMA.
International - All maps are drawn using a symbol set similar to the IALA symbol set.
Symbol/Text Size— Small, Medium, and Large: controls the screen size of the symbol/name.
Light Sectors— Off, Auto, On: controls the drawing light sectors on the map. Color units indicate
the actual color of each sector using the color of the light.
Off— No light sectors are ever drawn.
Auto— Light sectors appear when you point to them with the map cursor.
On— Light sectors are drawn for all lights that have them.
Navaids Tab
Nav Line Tab—
Heading Line— On/Off: draws an extension from the end of the boat icon in the direction of
travel.
Bearing Line— On/Off: toggles the black/white line which points to the current navigation point.
28
Course Line— Auto, Off, 20 ft.-800 mi.: sets the maximum zoom scale at which the desired
course line should appear on the screen.
Track Tab— Saved Tracks/Track Log
Zoom— Auto, Off, 20 ft.-800 mi.: sets the maximum scale at which the feature should appear on
the screen. Some types of data only display up to certain zoom scales.
Other Tab—
Reference
Map Page: Options
Accuracy Circle— On/Off: toggles the circle “On” and “Off”. The circle represents the approximate
accuracy of the unit based on EPE, DOP, and basemap quality. Your position is within the circle.
Lat/Lon Grid— Text— None, Small, Medium, and Large: controls the screen size of the name.
Zoom— Auto, Off, 20 ft.-800 mi.: sets the maximum scale at which the feature should appear.
Map Outlines— On/Off: toggles the coverage boxes for BlueChart/MapSource data “On” and “Off”.
From the map setup page, you can access the following menu options by pressing MENU:
• Defaults— restores settings back to factory settings for the tab highlighted.
Nav Line Tab
• All Map Defaults— restores settings back to factory settings for all tabs.
• Set Up Page Layout — the layout of the data fields may be changed to show more fields (with a
smaller number size) or less fields (with a larger number size). You may also choose to show a Compass
Tape on the Map Page only.
To set up the page layout:
Track Tab
1. Press the MENU key to display the Page options.
2. Highlight ‘Set Up Page Layout’ and press ENTER. (continued)
3. The current setting displays, press ENTER to change. Use the ARROW KEYPAD to highlight the desired
setting, then press ENTER.
4. Press QUIT when finished.
Other Tab
• Change Numbers — allows you to specify the type of data displayed in each data field used on the
map display. This option is available from any of the main pages. See page 19 for instructions on changing data field numbers.
29
Reference
Map Page: Options
Changing Page Layout
Highlight the field you
wish to change
30
The following data options are available for data fields on the main pages:
• BEARING – Compass direction from your position to destination
• COMPASS – Compass ribbon
• COURSE – Desired Track
• DEPTH – Depth below transducer
• DIST TO DESTINATION – Distance to final waypoint
• DIST TO NEXT – Distance to next waypoint
• ELEVATION – Elevation above/below MSL (Mean Sea Level)
• ETA AT DESTINATION – Estimated Time of Arrival to final waypoint
• ETA AT NEXT – Estimated Time of Arrival to next waypoint
• GPS ACCURACY – Shows estimated GPS accuracy
• HIGHWAY – Smaller version of the Highway Page
• MAXIMUM SPEED – Fastest speed the unit has traveled
• MOVE AVERAGE SPEED – Average moving speed
• MOVE TRIP TIME – Time unit has been moving for a trip
• OFF COURSE – Distance from desired track
• POINTER – Arrow points to your destination
• POSITION – Current position coordinates
• SONAR – Compressed view of sonar data
• SPEED – Speed over ground
• TIME OF DAY – Current time
• TIME TO DESTINATION – Time to final waypoint
• TIME TO NEXT – Time to next waypoint
• TO COURSE – Bearing to desired track
• TOTAL AVERAGE SPEED – Total average speed
• TOTAL TRIP TIME – Total travel time of trip, stopped and moving
• TRACK – Current compass direction of travel
• TRIP ODOMETER – Trip Odometer
• TURN – Directional amount of turn needed to match bearing
• VELOCITY MADE GOOD – Velocity Made Good to destination
• VOLTAGE – Current voltage reading being received by unit
• WATER SPEED* – Speed through the water
• WATER TEMP. LOG** – Timeline graph of the transducer’s temperature reading.
• WATER TEMPERATURE** – Water temperature
Reference
Map Page: Options
*If equipped with a speed sensor or speed capable transducer.
**If equipped with a temperature sensor or temperature capable transducer.
NOTE: COMPASS, HIGHWAY, POSITION, SONAR, and WATER TEMP. LOG are only available on Large and Huge
sized data fields.
• Turn Declutter On/Off — toggles between showing spot soundings and map outlines for easier
viewing.
Choose the type of data
you wish to display.
Map Setup
Menu Options
31
Map/Sonar Split Page
Reference
Map/Sonar Split Page
The Map/Sonar Split Page combines the Map Page on the left half with the Sonar Page on the right
by default. The menu options for this page are the same as the Map Page. Any setting changes made from
the Map/Sonar Split Page will also affect the Map Page. One additional option is that you may adjust the
size of the split left or right.
• Size Split — enables width adjustment of the Map/Sonar Split Page . You may adjust the size of
the map/sonar split window anywhere from 1/3 to 2/3 width from the edges of the screen.
To resize the Map/Sonar Split Page:
1. From the Map/Sonar Split Page, press MENU.
2. Highlight ‘Size Split’ and press ENTER.
3. Use the ARROW KEYPAD to move the horizontal double-arrow LEFT or RIGHT until the desired vertical width line shows, then press ENTER.
Map/Sonar Split Page
You may resize the split to the
left or right.
32
Sonar Page
The Sonar Page is where your GPSMAP 178/178C Sounder becomes a powerful fishfinder. Fish are
displayed as colored arches (178C), arches (178) or as fish icons in three different sizes. Thermoclines
are shown as shades of blue (178C) or as a grayscale (178). The sonar display may also be set to show a
split screen view of a zoomed portion of the sonar, bottom lock (display scaled from the bottom up), or a
combination of these options (see pg. 34). For example, you may choose to show dual frequency at a 2X
zoom (Dual 2X) on one half and normal range dual frequency (Dual) returns on the other half. The current display mode is displayed at the bottom of each sonar display. For more information on understanding sonar and the display, see page 14 and Appendix G.
Reference
Sonar Page
Using the Adjustment Menu
The Adjustment Menu allows direct access to the settings and features most commonly used on the
Sonar Page. The currently selected option appears in the upper left of the display.
To select an adjustment option from the Sonar Page:
Sonar Page
1. Press the ARROW KEYPAD LEFT/RIGHT to scroll through the options in the upper left of the display,
then press ENTER to access the desired option’s adjustment window.
OR:
1. Press MENU, highlight ‘Adjustments’ and press ENTER. A list of all options and their current settings
appears, with the selected option highlighted. Press UP/DOWN on the ARROW KEYPAD to select the
desired option and press ENTER to access the adjustment window.
To easily exit any of the adjustment options, press the QUIT key.
To change an Adjustment Menu setting:
1. Select an adjustment option to change using one of the two methods described above. The adjustment window automatically times out and disappear when idle for 20 seconds.
2. Press the ARROW KEYPAD UP/DOWN to place the pointer or setting bar at the desired setting,
range or percentage (Off, 1-100%).
3. Press ENTER or QUIT to exit the adjustment window; or press LEFT/RIGHT on the ARROW KEYPAD
to view another adjustment window.
Press MENU and highlight ‘Adjustments’ to see a list of all options and
their current settings.
33
To change a setting back to ‘Normal’ or ‘Auto’:
Reference
Sonar Page:
Adjustment Menu
Zoom Adjustment
Range Adjustment
4X Split Zoom Display (Dual Frequency Mode)
34
1. On the adjustment window for the desired option, press MENU.
2. Select the desired setting and press ENTER.
Adjustment Menu Options
Range— sets the display depth range used for viewing. The unit can be set to automatically track
the bottom or set to a user-specified depth range. Auto mode displays the most information possible
while continuously showing the bottom.
Zoom— used to quickly select a display zoom scale or split the display. When a scale other than ‘No
Zoom’ is selected, the Adjustment Menu displays a new selection labeled ‘View.’ Split screens display
the same frequency (50kHz, 200kHz, or Dual) on both sides. The Zoom setting is divided into six
display levels:
• 2X Split: shows two reduced-size sonar pictures at the same time. The right half of the display
screen shows the complete sonar picture at its original scale. The left half shows a portion of the
original picture at 1/2 depth scale.
• 2X Zoom: displays the 2X zoomed picture on the full screen and does not show the original
depth scale.
• 4X Split: shows two reduced pictures; the right at the original depth scale and the left at 1/4 the
original depth scale.
• 4X Zoom: displays only the 4X zoomed picture on the full screen.
• Btm (Bottom) Split: shows two reduced pictures; the right at the original depth scale and the left
showing sonar returns from the bottom up. All target depths read as a distance from the bottom.
• Btm (Bottom) Lock: displays only the Bottom Lock picture (returns from the bottom up) on the
full screen.
Once activated, the zoomed picture becomes the Sonar Page display. You may also cycle through the
sonar zoom display levels by pressing the IN or OUT keys. The Zoom function can be deactivated by
pressing the OUT key until the ‘No Zoom’ setting appears.
View/Span— available when a Zoom scale other than ‘No Zoom’ is selected. The ‘View’ or ‘Span’
setting is used to change the viewing range of a zoomed display. If the Zoom is set to 2X split or 4X
split, only the zoomed portion on the left side of the screen is affected by the change. If the Zoom is
set to Bottom Split or Bottom Lock, ‘Span’ adjusts how far off the bottom the unit displays data. In
Zoom mode, you can control the view of the left side of the split.
Gain— allows you to control the sensitivity of the unit’s receiver. This provides some flexibility in
what is seen on the display. To see more detail, increase the receiver sensitivity by selecting a higher
gain percentage. If there is too much detail or if the screen is cluttered, lowering the sensitivity may
increase the clarity of the display.
Target Level— adjusts the color range of a return (or target). A Color Bar (see also page 39) appears
on the right side of the screen as you adjust this setting. A higher percentage setting results in stronger-signaled returns (see page14). This setting does not increase/decrease the unit Gain.
Whiteline— controls how the unit displays information about the bottom type (hard or soft).
With the Whiteline ‘Off’, the bottom return displays as red and contains no information on bottom
hardness. With Whiteline set at ‘Normal’ or 1-100%, the bottom return becomes white with a red
line indicating where the water meets the bottom. To turn the Whiteline Off, press the ARROW
KEYPAD DOWN until the setting bar is all the way at the bottom of the range and reads “Off”. See
page 114 for more detail on this feature.
Frequency— allows you to choose a transducer frequency. Frequency refers to the “pitch” of the
sound that the transducer sends and receives. You may choose ‘200kHz’, ‘50kHz’, or ‘Dual’ frequency.
Depth Line— adds a horizontal depth line across the display which is used to measure the depth
of underwater objects. The depth of the line appears in a box on the right side of the line. Press UP
or DOWN on the ARROW KEYPAD to control the position of the line on the graph. The depth is
displayed in a window on the right side of the line. To turn the Depth Line Off, press the ARROW
KEYPAD UP until the setting bar is all the way at the top of the range and reads “Off”.
Reference
Sonar Page:
Adjustment Menu
View Adjustment
Gain Adjustment
Target Level Adjustment
Whiteline Adjustment
Frequency Adjustment
35
Reference
Sonar Page Options
Depth Line
Adjustment
Noise Reject— helps filter unwanted noise from the graph. The ‘Noise Reject’ tool can be turned
‘Off’, set to ‘Normal’ (automatically adjusts for optimum viewing), or to a fixed 1-100% setting.
Increasing the Noise Reject setting decreases the sonars sensitivity. At high Noise Reject settings the
unit may not show all fish or structure. To turn the Noise Reject Off, press the ARROW KEYPAD
DOWN until the setting bar is all the way at the bottom of the range and reads “Off”.
Scroll— adjusts the rate that the graph scrolls from right to left. If you are sitting still or the graph is
moving too fast, slowing the scroll rate, or pausing it can be beneficial.
Sonar Page Options
The GPSMAP 178/178C Sounder’s Sonar Page features a menu page that provides access to additional functions and to layout and data field options.
To display the Sonar Page options:
Noise Reject
Adjustment
1. Press MENU.
To select a menu option:
Scroll
Adjustment
1. Use the ARROW KEYPAD to highlight the desired option and press ENTER.
The following options are available:
• Adjustments — lists the Adjustment Menu options and their current settings (see page 15).
To change an Adjustment setting:
1. On the Adjustment options list, use the ARROW KEYPAD to highlight the desired option and press
ENTER.
2. Use the ARROW KEYPAD to make the desired change and press ENTER.
Sonar Page Menu Options
36
• Show/Hide Pointer — allows you to reference sonar items and mark underwater waypoints. This
makes it easier to find and use an object such as a stump for a future fishing location. When using
this feature, the Sonar Page pauses. The pointer does not move off the paused display and cannot
show an area that has scrolled off the screen. The depth is updated while the display is paused, but
the unit does not show any new sonar data until the standard Sonar Page is resumed. You may see
a discontinuity from where the sonar information stops to where it starts again.
To mark an underwater waypoint:
Reference
1. From the Sonar Page, press MENU, highlight ‘Show Pointer’ and press ENTER to pause the screen
movement.
Sonar Page Options
2. Use the ARROW KEYPAD to move the cursor onto the target (underwater drop off, stump, etc.) you
want to mark. The data window at the top of the screen displays the cursor’s depth, coordinates, and
bearing and distance from your current position.
3. Press and hold ENTER/MARK. The New Waypoint Page appears with the waypoint’s coordinates,
default three-digit name, and pointer depth automatically filled in.
Data Window
4. To change the name, symbol, or depth, highlight the appropriate field and press ENTER. Make your
changes and press ENTER when done.
5. When done, move the field highlight back to the ‘OK’ prompt and press ENTER.
6. To return to the standard Sonar Page, press QUIT; or press MENU, then highlight ‘Hide Pointer’ and
press ENTER.
• Show/Hide Numbers — toggles showing/hiding the data fields on the sonar display.
Pointer
‘Show Pointer’ option enabled
• Size Split — enables width adjustment of the Sonar Page split screen. This option is only available
when a split screen zoom scale is selected. You may adjust the size of the split window anywhere
from 1/4 to 3/4 width of the right half of the Sonar Page.
To resize the Sonar Page split screen:
1. From the Sonar Page split screen, press MENU.
2. Using the ARROW KEYPAD, highlight ‘Size Split’ and press ENTER.
3. Move the horizontal double-arrow LEFT or RIGHT using the ARROW KEYPAD until the desired vertical width line shows, then press ENTER.
4. If you wish to cancel this operation, press QUIT or press MENU, highlight ‘Cancel Resize’ and press
ENTER.
‘Show Numbers’
option enabled
37
Reference
Sonar Page Options
Double-Arrow
• Set Up Sonar — jumps to the Sonar tab of the Main Menu, which contains sonar configuration settings that should not require frequent change. You may also press MENU twice from any
screen, then highlight the ‘Sonar’ tab using the ARROW KEYPAD. Press RIGHT on the ARROW
KEYPAD to access the selection fields. Each time the Setup Menu is accessed, the unit returns to
the last edited selection field.
To change a setting on the Sonar tab:
1. Using the ARROW KEYPAD, highlight the desired field and press ENTER and the available options
appear.
2. Highlight the desired setting and press ENTER.
3. Press QUIT to return to the Sonar Page or previous page.
Resizing the Split Sonar Display
‘Size Split’ Menu
Options
Fish Symbols Off— All available information
is displayed.
Fish Symbols — allows you to determine how the graph displays underwater targets and background information. If Fish Symbols are set to ‘Off’, the unit displays all of the available information
about the underwater environment. If a fish symbol is selected, the graph displays only the information related to that symbol. Actual fish returns may not always appear as perfect arches (like in
simulator mode), due to the speed, fish orientation, and/or other conditions.
Suspended targets displays as fish symbols.
Background information is displayed.
Water Type — since sound waves travel through ‘Fresh’ and ‘Salt’ water at different rates it is necessary to select the ‘Water Type’ to ensure accurate readings on the unit.
Same as above with the target depth attached.
Suspended targets display as fish symbols. No
background information is displayed.
Same as above with target depth attached.
38
Sonar Tab Options
Depth Number — controls the efficiency of the digital depth update rate. ’Fast Update’ updates
more quickly and is recommended for low-noise, deeper water (>50 ft.). ‘Auto’ is best for shallow
water or high noise areas, has a slower screen update and is best used if you travel a wide variety of
depths.

If the unit is unable to track the bottom for any reason, the digits in the depth window
flashes on and off to alert you that the unit is not tracking the bottom.
Scale — controls the depth ‘Scale’ displayed vertically along the right side of the graph. The depth
‘Scale’ can be configured to display four different ways: as an ‘Overlay’, in the ‘Corners’, with
‘Basic’, or ‘No Scale’.
Reference
Sonar Tab Options
Color Bar — shows a gradient scale of the current Target Level setting (see page 35).
Flasher — with the ‘Flasher’ active, a graphic Flasher representation is displayed on the far right
side of the graph. This graphic Flasher displays structure and bottom returns much the same as a
true Flasher. You may find this feature particularly useful when using ‘Fish Symbols’.
Temperature Graph — toggles On or Off the display of a temperature graph on the Sonar Page.
The graph is synchronized with the returns on the sonar display.
Background Color — (178C) sets the background color on the Sonar Page to Black, Blue, or
White. (178) sets the background color to Black or White.
Keel Offset — used to offset the surface reading for the depth of a keel. This makes it possible to
measure depth from the bottom of your keel instead of from the transducer’s location. Enter a positive number to offset for a keel, or enter a negative number to compensate for a large vessel that
may draw several feet of water. The ‘Keel Offset’ is reflected in the depth reading.
Main Menu—Sonar Tab
(172C)
Depth Scale (Overlay)
Map Split Sonar Detail — controls Map/Sonar Page sonar split range scale. ‘Full Range’ shows
right side scale of 2X or 4X split Sonar Page. ‘Maximum Detail’ displays what is shown on the left
side of a split sonar screen.
Calibrate Water Speed — this is only available if you are using a speed-capable transducer/sensor.
Calibration is required to ensure that the Water Speed displayed on your unit is accurate. The unit
automatically uses the GPS ground speed, if it is available, for comparison on the calibration. If a
GPS ground speed is not available, use either your boat’s speedometer reading (not always accurate), or a stopwatch to determine your speed over a certain distance (distance / time = speed). It is
recommended that the calibration take place in water having little or no current.
Color Bar
Flasher
39
To calibrate the water speed:
Reference
Sonar Tab Options
Keel Offset:
Transducer at Surface
Enter (+) positive
number to show depth
from bottom of keel
1. On the Sonar tab, use the ARROW KEYPAD to highlight ‘Calibrate Water Speed’ and press ENTER.
2. Bring the boat to a cruising speed. The top ground and uncalibrated water speeds are shown at the
bottom of the calibration window. Note your top water speed, then stop the boat and press ENTER.
3. By default, the top ground speed is automatically shown in the ‘What was your top water speed?’
field. If a ground speed is not available, the top uncalibrated water speed is used instead. If the new
speed is correct, highlight ‘OK’ and press ENTER. If you wish to manually enter a calibration, press
ENTER on the speed field, enter a new speed and press ENTER.
4. You may also press MENU from the calibration screen and choose ‘Use Top Ground Speed’ to default
back to ground speed or ‘Use No Calibration’ to use the speed sensor’s uncalibrated speed.

Keel Offset: Transducer
at Bottom of Keel
Enter (-) negative number to
show depth from surface
NOTE: If the boat is not moving fast enough or the speed sensor is not outputting a
speed, you see a “Boat Is Not Moving Fast Enough To Calibrate” message at the bottom
of the display. Check that the speed sensor wheel is moving or safely increase boat
speed. If there is a problem with the speed sensor/unit or if a speed senor is not installed,
a “Water Speed Sensor Is Not Working” message appears at the bottom of the display.
Check connections of speed sensor cables.
• Set Up Page Layout — layout of the data fields may also be changed to show more fields (with a
smaller number size) or less fields (with a larger number size). See page 29.
• Change Numbers — allows you to specify the type of data displayed in each data field. For detailed
instructions on changing the data fields on the Sonar Page, see pages 30-31.
• Page Defaults — restores the Sonar Page settings to the original factory setup.
To restore default settings to the Sonar Tab:
1. Press MENU. With ‘Page Defaults’ highlighted, press ENTER.
Calibrating the
Speed Sensor
40
Compass Page
The GPSMAP 178/178C Sounder features two different navigation pages: Compass and Highway.
Whenever a NAV goto, Follow Track (TracBack), or Follow Route have been activated, the GPSMAP
178/178C Sounder’s Compass Page guides you to your destination with digital readouts and a graphic
compass display, which includes a bearing pointer. Use this page (instead of the Highway Page) when your
desired path may be varied in direction. The middle of the page features a rotating ‘compass ring’ that shows
your course over ground (track) while you’re moving. Your present course over ground is indicated at the
top of the compass ring. A bearing pointer arrow, in the middle of the compass ring, and a bearing ‘bug’
indicator on the outside of the compass ring, indicate the direction of the destination (bearing) relative to
the course over ground. The compass ring and pointer arrow work independently to show—at a glance—
the direction of your movement and the direction to your destination. For instance, if the arrow points up,
you are going directly to the waypoint. If the arrow points any direction other than up, turn toward the
arrow until it points up, then continue in that direction.

The bearing pointer, bearing bug and/or compass ring may point in various directions
when you are stationary or at very low speeds. Once you start moving, the pointer is
correct.
The GPSMAP 178/178C’s Compass Page features a menu page that provides access to layout and data
field options. The data window, located at the top of the page, provides a user-selectable layout of various
types of useful data. Each data field may be configured to display several data options.
Reference
Compass Page
Data Fields
Bearing
‘Bug’
Bearing
Pointer
Destination
Compass
Ring
To display the Compass Page options:
1. Press MENU.
To select a menu option:
1. Use the ARROW KEYPAD to highlight the desired option and press ENTER.
For detailed instructions on changing data fields and layout of the Compass Page, see pages 29-31.
41
Reference
Highway Page
Highway Page
When a Go To, TracBack, or route has been activated, the GPSMAP 178/178C’s Highway Page provides digital and graphic steering guidance to the destination. The top half of the Highway Page features
user-selectable data fields that display useful navigation data. The bottom section of the screen provides
visual guidance to the waypoint on a graphic highway display. The line down the center of the highway
represents your desired track line.
As you head toward your destination, the highway perspective moves to indicate your progress to the
waypoint and which direction you should steer to stay on course. If you are navigating a route, the Highway Page shows each route waypoint in sequence connected by a red “road” with a yellow line down the
middle, which is your desired track line. Nearby waypoints not in the active route can also be displayed.
The highway perspective scale may also be zoomed in or out to display a larger or smaller view of the
highway. Five settings are available from 1X to 16X, with a default setting of 8X.
Data Fields
To change the highway perspective scale:
Current Nav Point
1. Press the ZOOM IN or ZOOM OUT key to select the desired setting.
Route Waypoints
The Highway Page options menu provides access to functions and features relating to the Highway
Page and the layout options. The data window, located at the top of the page, provides a user-selectable
layout of various types of useful data. Each data field may be configured to display several data options.
The data window layout may also be changed to display additional data fields and change the actual size
of the data displayed.
Desired Track Line
Current Position
Zoom Scale
Highway Page
The GPSMAP 178/178C’s Highway Page features a menu options page that provides access to functions and features relating to the Highway Page and the layout options.
To display the Highway Page options:
1. Press MENU.
42
To select a menu option:
1. Using the ARROW KEYPAD, highlight the desired option and press ENTER.
The following options are available from the Highway Page menu:
• Set Up Highway— allows you to select what waypoints and tracks are shown on the Highway display. Use the ARROW KEYPAD and ENTER key to select/deselect the desired options. Four options
are available:
• Active Route Waypoints— all active route waypoints
• User Waypoints— only nearby waypoints
• Track Log— current active track log
• Saved Tracks— any saved track logs
• Set Up Page Layout— allows you to change the layout of the data fields to show more fields (with
a smaller number size) or less fields (with a larger number size). See page 29.
• Change Numbers— allows you to specify the type of data displayed in each data field used on the
map display. For detailed instructions on changing the data fields and layout of the Highway Page, see
pages 30-31.
Reference
Highway Page Options
Check or uncheck
the options you wish
to show/hide on the
Highway Page.
Preview Window
Selecting the ‘Setup Highway’
option takes you to the Hiway
tab of the Main Menu.
Active Route Page
When a route is activated in the GPSMAP 178/178C Sounder system, the Active Route Page shows
each waypoint of the active route, along with various, user-selectable types of data. For additional details
on the Active Route Page, see page 64.
Active Route Page
43
Reference
Creating Waypoints
Creating and Using Waypoints
The Garmin GPSMAP 178/178C stores up to 3000 alphanumeric waypoints with a user-defined icon,
comments, depth, or water temperature available for each waypoint. Waypoints can be created using
three basic methods:
• ENTER/MARK key– used primarily for marking your present position, the ENTER/MARK key
also provides options that allow you to select a map position or map item from the map display.
• Graphically– allows you to define a new waypoint position from the map display using the
ARROW KEYPAD. (For creating underwater waypoints, see page 37)
• Text Entry– allows you to enter a new waypoint’s coordinates manually (from a chart, etc.).
Marking Your Present Position
Highlight ‘OK’ and press ENTER to
use the default name and symbol.
The Garmin GPSMAP 178/178C’s ENTER/MARK key lets you quickly capture your present position
(or cursor or map item position) in order to create a new waypoint. You must have a valid position (2D
or 3D) fix to mark your present position. This can be determined by looking at the GPS tab on the Main
Menu.
To mark your present position:
1. Press and hold the ENTER/MARK key until the ‘New Waypoint’ window appears, then release it. You
see a default three-digit name and symbol for the new waypoint.
2. To accept the waypoint with the default name and symbol, press ENTER to confirm the highlighted
‘OK’ prompt.
3. To enter a different name, highlight the name field and press ENTER, then use the ARROW KEYPAD
to enter the new letters/numbers and press ENTER when done. You may use up to 10 alphanumeric
characters for the name.
Highlight a field and press ENTER
to enter a new symbol, name, comment, or depth.
44
4. To enter a different symbol, highlight the symbol field to the left of the name and press ENTER, then
use the ARROW KEYPAD to highlight the new symbol and press ENTER.
5. To enter optional comments, depth, or water temp, highlight the appropriate field and press ENTER,
then use the ARROW KEYPAD to enter a value and press ENTER.
6. To manually enter a set of coordinates, highlight the coordinates and press ENTER, then use the
ARROW KEYPAD to enter the new coordinates and press ENTER when done.
7. When done, use the ARROW KEYPAD to highlight ‘OK’ and press ENTER to save the waypoint into
memory.
Reference
Creating Waypoints
Creating Waypoints Graphically
Waypoints may also be quickly created with the Map Page cursor, which allows you to ‘point and
shoot’ at any map position or map feature to create a new waypoint. When you move the cursor over a
map item, you see a highlighted description of that item. The GPSMAP 178/178C uses the map item text
shown on the cartography as the default name and symbol for the new waypoint.
To create a new waypoint on an open map location:
1. Use the ARROW KEYPAD to move the cursor to the desired map position.
2. Press and quickly release the ENTER/MARK key to capture the cursor position (press and hold
ENTER/MARK to mark your present location, not the map cursor’s position).
3. The ‘New Map Waypoint’ Page appears. To accept the waypoint with the default name and symbol,
press ENTER.
To change the name, symbol, position, or add a comment, depth, or water temp, highlight the appropriate field and press ENTER. Make your changes and press ENTER when done. After entering and
confirming your changes, highlight ‘OK’ and press ENTER.
Creating a waypoint on
an open map location.
To create a new waypoint from a map feature:
1. Use the ARROW KEYPAD to move the cursor and highlight the desired map feature.
2. Press ENTER/MARK to capture the cursor position. An Information page for that map feature
appears. Use the ARROW KEYPAD to highlight ‘Create Wpt’ and press ENTER.
3. The ‘New Waypoint’ Page appears. To accept the waypoint with the default name and symbol (based
on the map feature), highlight ‘OK’ and press ENTER.
To change the name, symbol, position, or enter comments, depth, or water temp, highlight the appropriate field and press ENTER. Make your changes and press ENTER. After entering and confirming
your changes, use the ARROW KEYPAD to highlight ‘OK’ and press ENTER.
Using a map item to create
a new waypoint.
45
Reference
Creating Waypoints
Additional Options For Creating Waypoints
Waypoints may also be created by manually entering position coordinates through the Points tab of
the Main Menu. This method can be useful for creating a waypoint at a specific latitude/longitude position from a chart.
To create a new waypoint by entering location coordinates:
1. Press MENU twice to display the Main Menu. Highlight the ‘Points’ tab and press MENU.
2. Highlight ‘Create Waypoint’ and press ENTER. The ‘New Waypoint’ Page appears, with the next available waypoint number and the receiver’s last know position as the default name and position.
3. Use the ARROW KEYPAD to highlight the position field and press ENTER. Use the ARROW
KEYPAD to enter the desired position coordinates and press ENTER when finished.
4. To change the name, symbol, or enter comments, depth, or water temp, highlight the appropriate field
and press ENTER. Make your changes and press ENTER when finished.
Highlight the position field and use the
ARROW KEYPAD to enter the desired
position coordinates.
5. Use the ARROW KEYPAD to highlight ‘OK’ and press ENTER to save the waypoint.
A waypoint may also be created by “projecting” the distance and bearing from a specific location to a
new location. Start by accessing the ‘New Waypoint’ Page or the ‘New Map Waypoint’ Page.
To create a new waypoint by projecting its location:
1. To project the waypoint from your current location, be sure the reference field reads ‘Current Position’
(if not, highlight the field and press ENTER, highlight ‘Current Position’ and press ENTER).
2. To select a map location from which to project a waypoint, highlight the reference field and press
ENTER. The ‘Find’ screen appears. Highlight ‘Other Position’ and press ENTER. Use the zoom IN key
and ARROW KEYPAD to highlight the desired position on the map and press ENTER.
Select a point from which to
project a new waypoint.
46
3. To select another location from which to project a waypoint, highlight the reference field and press
ENTER. The ‘Find’ screen appears. Highlight the desired type of location (waypoints, cities, etc.) and
press ENTER. Use the submenus to narrow down your search (for more information see ‘Find’ on
page 65). Highlight the desired location and press ENTER. With ‘OK’ highlighted, press ENTER again.
4. Highlight the distance and/or bearing fields in the reference field and press ENTER. Use the ARROW
KEYPAD to enter the projected distance and/or bearing from your current position for the new
waypoint and press ENTER.
5. Make any other desired changes to the new waypoint data (name, symbol, etc.), then highlight ‘OK’
and press ENTER to save the waypoint.
Reference
Creating Waypoints
Waypoint Menu Options
Two additional options are available by pressing MENU on the New Waypoint and New Map
Waypoint Pages: Append To Route and Move Waypoint. (these menu options also appear on the
Waypoint Edit and Waypoint Review Pages).
Waypoint Options Menu
• Append to Route— Adds the new waypoint to the end of a route.
• Move Waypoint— Allows you to move the waypoint to a new location on the map display.
To append a new waypoint to a route:
1. Select ‘Append To Route’ from the options menu.
2. The ‘Select Route’ screen appears. Highlight the desired route or select ‘New Route’ and press
ENTER.
3. With ‘OK’ highlighted, press ENTER to save the waypoint.
To move a waypoint:
1. Select ‘Move Waypoint’ from the options menu.
2. The selected waypoint is centered and highlighted on a map display. Use the ARROW KEYPAD to
move the waypoint to the new position and press ENTER. Press QUIT to exit.
Use the ARROW KEYPAD to move the
waypoint to a new position on the map.
47
Reference
Reviewing/Editing Waypoints
Reviewing and Editing Waypoints
Once you have created and stored a waypoint, it may be modified, reviewed, renamed, moved, or
deleted at any time through the Waypoint Review and Waypoint Edit Pages.
To access the Waypoint Review Page:
1. Use the ARROW KEYPAD to highlight the desired waypoint on the Map Page.
2. Press ENTER to display the Waypoint Review Page. If the waypoint is located on a map feature, or on
a MapSource or BlueChart feature, the Waypoint Review Page includes additional information tabs
about the other features at that location.
To access the Waypoint Edit Page:
1. Press MENU twice to view the Main Menu. Use the ARROW KEYPAD to highlight the ‘Points’ tab,
then highlight the desired waypoint from the ‘User’ or ‘Proximity’ lists.
Waypoint Review Page— Highlight ‘OK’ and
press ENTER to exit/save changes.
2. Press ENTER to display the Waypoint Edit Page. If the waypoint is located on a map feature, or on a
MapSource or BlueChart feature, the Waypoint Edit Page does NOT display the details of the other
map features.
From the Waypoint Review and Edit Pages, you may change the name, symbol, comment, position
coordinates, depth, or water temp for the selected waypoint. Once the changes have been made, highlight
‘OK’ (Waypoint Review Page) or ‘Next’ (Waypoint Edit Page) and press ENTER to save them.
To change the waypoint name:
1. Highlight the waypoint name field and press ENTER.
2. Use the ARROW KEYPAD to enter a new name and press ENTER when done.
To change the waypoint symbol:
Changing a Waypoint symbol.
48
1. Highlight the waypoint symbol field to the left of the waypoint name and press ENTER.
2. Use the ARROW KEYPAD to select the desired symbol and press ENTER when done.
To change the comment/position coordinates/depth/water temperature:
Reference
1. Highlight the desired field and press ENTER.
2. Use the ARROW KEYPAD to edit/enter the data. To drop to the next line, press to the right on the
ARROW KEYPAD. Press ENTER when done.
Editing Waypoints
On the Waypoint Review and Waypoint Edit Pages, you may also delete the selected waypoint, view
the waypoint on the map, and move the waypoint on the map.
To delete a waypoint:
1. On the Waypoint Review/Waypoint Edit Page, use the ARROW KEYPAD to highlight ‘Delete’ and
press ENTER.
2, With ‘OK’ highlighted, press ENTER again to confirm the deletion.
Symbol
Name
To view and move a waypoint on the map:
1. From the Waypoint Review/Waypoint Edit Page, highlight ‘Show Map’ and press ENTER. The waypoint
is highlighted on a map screen with an information window that shows the waypoint name, position
and distance and bearing from your current position.
Comment
2. To move the waypoint, press ENTER. A ‘MOVE’ label now appears under the cursor arrow. It may be
necessary to use the IN and OUT keys to zoom the map.
Coordinates
3. Use the ARROW KEYPAD to move the waypoint to a new position. As you move the cursor around
the map display, the information window at the top changes to show the distance, bearing, and position of the map cursor (in relation to the waypoint’s original position), and a description of where the
cursor is on the map. If you wish to stop the move process, press QUIT.
Depth
Water
Temperature
Waypoint Edit Page
4. With the pointer at the desired position, press ENTER. To return to the Waypoint Edit/Waypoint
Review Page, press QUIT.
On the ‘Show Map’ map display, an additional option is available by pressing MENU:
• Point to on Map Page— returns to the highlighted waypoint on the main Map Page (exits the
Waypoint Review/Waypoint Edit Page).
49
Reference
Waypoint Lists
Submenu Tabs
Waypoint Lists
The GPSMAP 178/178C’s Main Menu Page features two waypoint submenu tabs, ‘User’ and ‘Proximity’, that let you manage a large number of waypoints quickly and efficiently. The submenu tabs also
provide a continuously updated proximity waypoint alarm function that can be used to define an alarm
circle around submerged hazards, shallow waters, etc.
To access the waypoint submenus of the Main Menu:
1. Press MENU twice, highlight the ‘Points’ tab using the ARROW KEYPAD, then highlight the desired
submenu tab.
User Waypoint List
Main Menu—Points Tab
The ‘User’ submenu of the Points tab displays a master list of all waypoints currently stored in
memory. From the User list, you may review, edit, rename, or delete individual waypoints, or delete all
user waypoints. The total number of stored and available waypoints is displayed at the bottom of the
User page, with the stored waypoints arranged in numerical/alphabetical order.
To scroll through and review the waypoint list:
1. With the ARROW KEYPAD, highlight the ‘Points’ tab on the main menu, then highlight ‘User’.
2. Use the ARROW KEYPAD to scroll through the list in the desired direction.
3. Press ENTER to review the highlighted waypoint on the ‘Waypoint Edit’ Page (see page 48 for
detailed information on reviewing and editing waypoints).
4. With ‘Next’ highlighted, press ENTER to return to the list. The field highlight automatically moves to
the next waypoint in the list.
Options Menu
50
The following options are available by pressing MENU while highlighting the Points tab, the User
submenu or one of the User waypoint names:
• Create Waypoint— allows you to create a waypoint. (See page 44)
• Delete Waypoint— deletes selected waypoint from list and any route in which it was used.
• Delete By Symbol— deletes waypoints that use the same symbol.
• Delete All— deletes all waypoints from the unit.

Once a waypoint is deleted from the list, it cannot be recovered from the unit. It is
advisable to backup important waypoints to a computer using an optional PC cable and
interface software, save them to a data card, or write them down by hand.
To delete an individual waypoint from the ‘User’ list:
Reference
Waypoint Lists
1. Use the ARROW KEYPAD to highlight the waypoint to be deleted.
2. Press MENU, highlight ‘Delete Waypoint’ and press ENTER.
OR, press ENTER, highlight ‘Delete’ and press ENTER.
3. Press the ENTER key to confirm the deletion warning.
Name
Field
To delete waypoints by symbol:
1. From the ‘User’ tab, highlight the waypoint to be deleted and press MENU, then select ‘Delete By
Symbol’ and press ENTER.
2. Use the ARROW KEYPAD to highlight the symbol of the waypoint(s) to be deleted and press
ENTER.
3. Press ENTER to confirm. Choose ‘Cancel’ or press QUIT to stop the deletion.
Waypoint
List
To delete all user waypoints:
1. Press the MENU key to select the options window.
2. Use the ARROW KEYPAD to highlight ‘Delete All’ and then press ENTER.
3. Highlight ‘OK’ and press ENTER to confirm.
Proximity Waypoint List
The ‘Proximity’ submenu of the Points tab lets you define an alarm circle around a stored waypoint
position, and can be used to help you avoid reefs, rocks, or restricted waters. Up to ten waypoints may
be listed, with a maximum alarm radius of 99.99 nautical or statute miles or kilometers. If a proximity
alarm circle overlaps with an existing alarm circle, the message ‘Proximity Overlaps Another Proximity
Waypoint’ appears. Since the unit only alerts for one of the overlap points, use caution when navigating
in these areas. If you enter an alarm circle overlap, you are only alerted to the closest proximity waypoint.
You can also search for a waypoint by name:
1. Highlight the name field and press ENTER.
2. Use the ARROW KEYPAD to select the first letter of
the name.
3. Move to the RIGHT and enter the second letter if you do
not see it on the list below.
4. Repeat this until the name appears. Press ENTER when
you see the name.
5. Highlight the name on the list and press ENTER again
to review the waypoint. When done, highlight ‘OK’ and
press ENTER.
51
To add a proximity waypoint:
Reference
1. Use the ARROW KEYPAD to highlight an empty space on the Proximity list and press ENTER. The
‘Find’ screen appears. Highlight ‘Waypoints’ and press ENTER.
Waypoint Lists
2. Use the ARROW KEYPAD to highlight the desired waypoint from the ‘By Name’ or ‘Nearest’ tab lists.
The Waypoint Review Page appears for the selected waypoint.
3. With ‘OK’ highlighted, press ENTER to confirm. The distance field is now highlighted.
4. Press ENTER to begin entry of the proximity radius.
5. Use the ARROW KEYPAD to enter a distance value (to 99.99 units) and press ENTER.
To turn proximity alarms on or off:
1. Use the ARROW KEYPAD to highlight the field below “Proximity Alarm” and press ENTER.
2. Select the desired ‘ON’ or ‘OFF’ setting and press ENTER.
Proximity Waypoints List
The following options are available from the ‘Proximity’ submenu of the ‘Points’ tab:
• Delete Alarm— removes selected waypoint from proximity list.
• Delete All— removes all waypoints from proximity list.
To display the waypoint menu options:
1. Using the ARROW KEYPAD, highlight the ‘Proximity’ tab and press MENU.
Proximity
Waypoint
Proximity
Circle
To clear one or all proximity waypoint(s) from the list:
1. Use the ARROW KEYPAD to highlight the proximity waypoint to clear and press MENU.
2. To clear a single alarm, highlight the ‘Delete Alarm’ option and press ENTER.
3. To clear all proximity waypoints, select the ‘Delete All’ option and press ENTER.
A dashed circle appears showing
the alert boundary for the
proximity waypoints.
52
4. Use the ARROW KEYPAD to highlight the ‘OK’ prompt and press ENTER to confirm.
Going to a Destination
Using the NAV key, the GPSMAP 178/178C provides three ways to navigate to a destination: Go To
Point, Follow Route, and Follow Track (TracBack). Once you are actively navigating, you see a straight
line that always runs from your current location to the destination on the Map Page. The easiest method
for selecting a destination is the ‘Go To’ function, which lets you select a destination point, then quickly
sets a direct course from your present position. If you highlight a point on a list or the map and press
NAV, ‘Go To <point name>’ appears in addition to ‘Go To Point’. The ‘Go To’ function can be accessed
from any list of points or graphically from the map display.
Reference
Going to a Destination
To activate a ‘Go To’ from a point list:
1. Press the NAV key.
2. Use the ARROW KEYPAD to highlight ‘Go To Point’ and press ENTER.
3. From the ‘Find’ menu, highlight ‘Waypoints’ and press ENTER. (You may also choose to go to other
points, such as Cities, Tide Stations, etc. from this list.)
4. Select a waypoint from the ‘By Name’ or ‘Nearest’ list, then press ENTER. To display the Waypoint
Review Page for the selected waypoint.
Choose a waypoint from either
the ‘User’ or ‘Nearest’ tab list.
5. With the ‘Go To’ button highlighted, press ENTER to begin navigation.
To stop navigation:
1. Press the NAV key. Use the ARROW KEYPAD to highlight ‘Stop Navigation’ and press ENTER.
Selecting a ‘Go To’ Graphically
A graphical ‘Go To’ may be used to select one of three items from the map display: an existing
waypoint, an on-screen map item (roads, rivers, cities, navaids, etc.), or a new map point (non-map
item). If you select a map item as the ‘Go To’ destination, the GPSMAP 178/178C automatically uses the
name of the map item, but the point is not stored in the waypoint list (see page 45 for creating waypoints
using map items). If you select a new map point (non-map item) as the ‘Go To’ destination, the GPSMAP
178/178C automatically creates or moves a waypoint named ‘MAP’ at the cursor position.
The waypoint or map item name
automatically appears when highlighted and NAV is pressed.
53
Reference
Going to a Destination/
TracBack Navigation
To activate an existing waypoint or map item as a ‘Go To’ from the map display:
1. Use the ARROW KEYPAD to highlight the waypoint or map item on the screen and press NAV.
2. With ‘Go To <waypoint name>’, press ENTER.
To activate a new map point (non-map item) as a ‘Go To’ from the map display:
1. Use the ARROW KEYPAD to move the arrow cursor to the desired position and press NAV.
2. With ‘Go To MAP Point’ highlighted, press ENTER.
To stop navigation:
1. Press the NAV key. Use the ARROW KEYPAD to highlight ‘Stop Navigation’ and press ENTER.
TracBack Navigation (Follow Track)
‘Go To MAP Point’ allows you to
navigate to a spot on the map that is
not a waypoint or map item.
The TracBack function allows you to retrace your path using the track log automatically stored in
the receiver’s memory, which eliminates the need to store waypoints along the way. TracBack routes are
created by reducing your track log into a route of up to 50 turns and activating an inverted route along
those points. Once activated, a TracBack route leads you back to the oldest stored track log point, so it’s a
good idea to clear the existing track log before you start your current trip.
To clear the track log and define a starting point for a TracBack route:
1. Press MENU twice to display the Main Menu.
2. Using the ARROW KEYPAD, highlight the ‘Track’ tab, then highlight the ‘Active’ tab to the right.
3. Use the ARROW KEYPAD to highlight ‘Erase’ and press ENTER.
4. Highlight ‘OK’ and press ENTER.
You must first save the track log before you can use the ‘Follow Track’ feature. The Save feature
allows you to store up to 15 track logs from certain times and dates.
Highlight ‘Save’ and press ENTER
to save an active track log.
54
To save a track log:
1. From the Main Menu, use the ARROW KEYPAD to highlight the ‘Track’ tab, then highlight the
‘Active’ tab to the right.
2. Use the ARROW KEYPAD to select ‘Save’ and press ENTER.
3. On the ‘Save Back Through’ window, highlight the desired time, date, or ‘Entire Log’ and press
ENTER.
4. Next, the track begins saving and then display the ‘Saved Track’ window when done. The default
name, distance, and number of points (700 maximum) are displayed.
Reference
TracBack Navigation
To change the name of the saved track, highlight the name field and press ENTER, make your
changes and press ENTER again.
Default Track name
To choose a color that is used to display the saved track line, highlight the field and press ENTER,
choose a Color and press ENTER again.
Total Distance
To display the track on the Map and Highway pages, highlight the check box to the left of ‘Show on
Map and Highway’ and press ENTER.
To view the track on the map, highlight ‘Review on Map’ and press ENTER. Press QUIT to exit the
Track Map window.
Change color of
track line
5. Highlight ‘OK’ and press ENTER to save the track.
Check this box to
display track
To activate a TracBack using the NAV key:
Total number of points
1. Press the NAV key, then highlight the ‘Follow Track’ option and press ENTER.
2. Highlight the track you wish to follow and press ENTER.
3. Choose either ‘Original’, which navigates you from the start to the end of your trip, or ‘Reverse’,
which navigates you from the end to the start of your trip and press ENTER.
Once a TracBack has been activated, the GPSMAP 178/178C takes the track log currently stored in
memory and divides it into segments called ‘legs’. Up to 50 temporary ‘turns’ (BEGIN, TURN 1, TURN
2, TURN 3,...., TURN X, END) are created to mark the most significant features of the track log in order
to duplicate your exact path as closely as possible. To get the most out of the TracBack feature, remember
the following tips:
• Always clear the track log at the point that you want to go back to (dock, etc.).
• The ‘Record Mode’ option on the track log setup page must be set to ‘Fill’ or ‘Wrap’.
• There must be at least two track log points stored in memory to create a TracBack route.
You must first save a track before using the ‘Follow
Track’ option. If there are no saved tracks, the message
“There are no saved Tracks to follow” appears after you
select ‘Follow Track.’
55
Reference
TracBack Navigation/
MOB: Man OverBoard
• If the track log interval is set to the ‘Time’ option, the route may not follow your exact path (keep
the interval set to ‘resolution’ for best performance).
• If the receiver is turned off or satellite coverage is lost during your trip, the TracBack draws a
straight line between any point where coverage was lost and where it resumed.
• If your track log’s changes in distance and direction are too complex, 50 waypoints may not mark
your path accurately. The receiver then assigns the 50 waypoints to the most significant points of
your track, and simplifies segments with fewer changes in direction.
To stop TracBack navigation:
1. Press the NAV key, highlight ‘Stop Navigation’ and press ENTER.
For more information on setting up the Track options and saved tracks, see page 75.
MOB Key
The MOB function allows you to
quickly activate a course back to
a location.
The GPSMAP 178/178C’s Man Over Board function (MOB) lets you simultaneously mark and set a
course to a position for quick response to emergency situations.
To activate the MOB function:
1. Press and hold the MOB key for two seconds.
2. Press ENTER to confirm and begin navigating to the MOB position.
Once a MOB has been activated, a ‘MOB’ waypoint with an international MOB symbol is created and
the unit is set on an active navigation to that point. Use any of the Navigation Pages to guide you back
to the MOB point. The MOB waypoint is stored in the waypoint list and may be deleted like any other
waypoint (see page 51).
To stop navigation to the MOB position:
Highlight ‘Stop Navigation’ and
press ENTER to stop navigating.
56
1. Press the NAV key, highlight ‘Stop Navigation’ and press ENTER.
Routes
The last way to navigate to a destination is to create a user-defined route. The Garmin GPSMAP
178/178C lets you create and store up to 50 reversible routes (numbered 1-50), with up to 50 waypoints
each. Routes can be created and modified in two ways. The first way is to ‘Edit on Map’ from the Route
Edit Map Page, allowing you to see each route graphically on-screen as you create, review, or modify the
route. The second way is to ‘Edit as Text’ from the Route Review Page, allowing you to see a list of the
waypoints as you create, review, or modify the route. All of the GPSMAP 178/178C’s route functions are
accessed through the Main Menu Page or the NAV key.
Reference
Creating a Route
To create a route graphically:
1. Press the MENU key twice to display the Main Menu Page. Use the ARROW KEYPAD to highlight
the ‘Route’ tab.
2. Press the MENU key to display the route options page. Select ‘New Route’ and press ENTER.
Or, highlight the first available blank slot in the Route List and press ENTER.
3. To add an existing waypoint or map item to the route, use the ARROW KEYPAD to highlight the
desired waypoint or map item on screen and press ENTER. Map items do not appear in the waypoint
list. To create a waypoint from a map item, see page 45.
Main Menu—Route Tab and
Route Options Menu
4. To add a new waypoint to the route, use the map cursor to select the desired map position and press
ENTER. Press ENTER again to confirm the new waypoint. You may also change the name, symbol,
and other properties of the new waypoint (see pages 48).
As you add each new waypoint to the route, the data window at the top of the map display shows
the waypoint/map item name, bearing and distance from your location, and coordinates of the cursor.
The bottom of the display shows you the number of available and used points. A route line appears
on the map to indicate each completed leg, and a dotted line appears to indicate the distance and
bearing to the arrow cursor from the last route waypoint.
5. Repeat steps 3 and 4 until you have finished defining all route waypoints.
6. When finished press QUIT twice to return to the Route List Page; or press MENU, highlight ‘Edit as
Text’ and press ENTER to return to the Route Review Page.
You see ‘ADD’ below the
cursor as you add points.
57
Reference
Creating a Route/
Following a Route
To create a route using text from the Route Review Page:
1. Press the MENU key twice to display the Main Menu Page. Use the ARROW KEYPAD to highlight
the ‘Route’ tab.
2. Press the MENU key to display the route options page. Select the ‘New Route’ option and press
ENTER.
Or, highlight the first available blank route slot and press ENTER.
3. Press MENU, select ‘Edit as text’ and press ENTER.
4. Use the ARROW KEYPAD to highlight the first field under the word “Waypoint” and press ENTER.
5. From the Find menu, highlight ‘Waypoints’ and press ENTER. (You may also choose from other points,
such as Cities, Tide Stations, etc. from this list.) Select a waypoint either “By Name” or using the
“Nearest” list and press ENTER. (See page 51 for searching for waypoints by name.)
Choose the type of point you
want to add to the route.
6. On the Point Review or Waypoint Review Page, ‘OK’ is automatically highlighted. Choose ‘Show Map’
and press ENTER to view the point on the map, then press QUIT to return to the Waypoint/Point
Review Page. With ‘OK’ highlighted, press ENTER to add the point to the route.
7. Repeat steps 4-6 until the desired route points have been entered. Press QUIT to return to the Route
List Page.
Following a Route
Once a route has been created, it can be activated and used for navigation with the NAV key. A route
may be followed in the same sequence as it was originally created, or inverted and followed from the end
point back to the beginning point.
To activate and follow a route:
Choose a waypoint from either
the ‘By Name’ or ‘Nearest’
tab list.
58
1. From any page, press the NAV key, then using the ARROW KEYPAD, highlight ‘Follow Route’ and
press ENTER. (If you highlight a route from the Route List or Route Review Page and press NAV, the
window automatically displays, ‘Follow <the route name>’.)
2. Highlight the route you wish to navigate and press ENTER.
3. Choose ‘Activate’ or ‘Invert and Activate’ and press ENTER. (‘Activate’ uses the route as is. ‘Invert and
Activate’ reverses the route then activates it.)
To deactivate (stop navigation) of a route:
Reference
Route List Page
1. Press the NAV key, highlight ‘Stop Navigation’ and press ENTER.
Route List Page
The GPSMAP 178/178C Route List Page (‘Route’ tab of the Main Menu) displays all the routes currently stored in memory, along with a descriptive name for each route. By pressing MENU while on the
Route List Page, the following menu options appear: ‘New Route’ (page 57), ‘Copy Route’, ‘Delete Route’,
or ‘Delete All’.
To select and follow a route:
1. On the Route List page, use the ARROW KEYPAD to highlight the desired route and press NAV.
2. With ‘Follow <route name>’ highlighted, press ENTER. Highlight ‘Activate’ or ‘Invert and
activate’ and press ENTER.
If you highlight a route name from
the Route List and press NAV, the
name automatically appears.
To deactivate (stop following) the route:
1. Press the NAV key, highlight ‘Stop Navigation’ and press ENTER.
To copy or delete a route:
1. From the Route List, using the ARROW KEYPAD, highlight the route you want to copy or delete and
press MENU.
2. Choose either ‘Copy Route’ or ‘Delete Route’ and press ENTER and with ‘OK’ highlighted, press
ENTER again to confirm a deletion. Copy uses the same route name with an additional number, starting at 1, at the end of the route name.
To delete all routes:
1. From the Route List, press MENU.
Route List Options Menu
2. Highlight ‘Delete All’ and press ENTER. With ‘OK highlighted, press ENTER again to confirm.
59
Route Review Page
Reference
Once you have created a route, the Route Review Page allows you to edit a selected route.
Route Review Page
To access the Route Review page:
1. Press MENU twice and highlight the ‘Route’ tab.
2. Highlight the name of the route you wish to review and press ENTER.
Route Name
Data Fields
Route Points
Data Totals
The Route Review page also allows you to enter a 15-character name for any listed route. By default
the name includes the first and last waypoints in the route.
To enter a custom route name:
1. From the Route Review page, highlight the name field and press ENTER to begin editing.
2. Use the ARROW KEYPAD to enter the desired name and press ENTER when finished.
Once you are on the Route Review Page, you may review the route points (waypoints or map items)
one at a time from the list.
To review individual route points:
1. Highlight the desired point and press ENTER.
2. On the Point Review window, you may choose ‘Next’ (highlight the next point on the route list), ‘Show
Map’ (show the point on a map window), or ‘Delete’ (permanently delete the waypoint from the unit)
and press ENTER. If the route point is a user waypoint, you may edit any of the waypoint properties
on the Waypoint Review Page (see pages 48 for details).
Once you are back on the Route Point List, the next point in the route is automatically highlighted.
This allows you to review each point on the route by repeatedly pressing ENTER.
Route Review Options Menu
Route Review
Options Menu
60
By pressing MENU on the Route Review page, the following options are available: Edit on Map, Add
Before, Remove, and Trip Planning.
• Edit on Map — review and modify the route displayed for each point (waypoint or map item) on
a map page. You may also use the cursor to insert a new route point on a route leg, and to review a
waypoint or map item.
To edit a route on the map:
Reference
Editing Routes
1. From the Route Review page, press MENU, highlight ‘Edit on Map’ and press ENTER.
To review a route point:
1. Highlight the point and press ENTER. The Review Page appears. Highlight ‘Next’ and press ENTER to
return to the map with the next route point highlighted.
To edit a route point:
1. Use the ARROW KEYPAD to highlight the desired route waypoint and press MENU.
A pop-up menu of editing choices appears, with the following options: Edit as Text (return to the
Route Review Page), Remove, Move (user waypoints only), and Add.
To remove a route waypoint:
Highlight a route point and
press ENTER to review it.
1. Highlight the ‘Remove’ option and press ENTER.
To move a route waypoint:
1. Highlight the ‘Move’ option and press ENTER.
2. Move the cursor to the new map position and press ENTER.
To add points to the beginning or end of the route:
1. With the map cursor, select the first route waypoint (to add waypoints to the beginning of the route)
or last (to add waypoints to the end of the route) and press MENU.
2. Highlight the ‘Add’ option and press ENTER.
3. Move the cursor to the new point or position and press ENTER.
4. If you are not adding an existing waypoint, press ENTER to confirm the new waypoint.
5. Repeat steps 3 and 4 to add additional waypoints or press QUIT to finish.
Choose ‘Next’ to center the map on the next
point in the route. You can step through the
points by repeatedly pressing ENTER.
61
Reference
Editing Routes
The GPSMAP 178/178C’s route edit mode also allows you to insert a new route point in any route leg
using the map cursor.
To insert a new point between two existing route waypoints:
1. Use the ARROW KEYPAD to select the leg in which you want to insert the new waypoint (the route
line highlights and changes to a dotted line when the leg is selected) and press ENTER.
2. Move the cursor to the new map position, existing waypoint, or map item (You see ’ADD’ below the
arrow and the route lines moves with the arrow) and press ENTER.
3. If you are not inserting an existing point, press ENTER to confirm the new waypoint.
4. Press QUIT to return to the Route Review Page.
• Add Before — Insert a waypoint into the route points list.
To insert a point into the route:
Highlight the route leg on which
you wish to insert a waypoint and
press ENTER.
1. From either the Route Review or Active Route Pages, use the ARROW KEYPAD to highlight the point
you wish to insert the new point before and press MENU.
2. Highlight ‘Add Before’ and press ENTER.
3. From the ‘Find’ menu, highlight ‘Waypoints’ and press ENTER. (You may also choose from other
points, such as Cities, Tide Stations, etc. from this list.) Select the point you want and press ENTER
twice. (See page 51 for searching for waypoints by name.)
• Remove — Remove a point (waypoint or map item) from a route. This option is available from
both the Route Review and Active Route Pages.
To remove a point from a route:
1. From either the Route Review or Active Route Pages, use the ARROW KEYPAD to highlight the point
to remove and press MENU.
Drag the route leg to an existing
waypoint, map item, or an open spot
on the map (shown) to create a new
route point.
62
2. Highlight ‘Remove’ and press ENTER.
• Trip Planning — The Route Review and Active Route Pages also display trip-planning information for
each leg or the entire route. Available information includes Course, ETA, Fuel (to point), Leg Distance,
Leg Fuel, Leg Time, Sunrise and Sunset (at point location), and Time To (point).
To use the trip planning feature:
Reference
Editing Routes
1. Highlight the desired route from the Route List and press ENTER to display the Route Review Page.
2. One of nine available planning figures appears to the right of each route waypoint and its distance.
Use the LEFT/RIGHT keys on the ARROW KEYPAD to select the desired item.
3. To enter planning information (from the Route Review Page only), press MENU and select ‘Trip Planning’ from the options list. Enter the figures for Speed, Fuel Flow, Departure Time, and
Departure Date.
4. Press QUIT to return to the Route Review Page.

NOTE: Fuel flow rates on your unit are measured in “units per hour”. System setting
changes for units of measure (statute, nautical or metric) do not affect the fuel flow measure. You should enter fuel flow rates based upon available information for your vehicle
(operator’s manual, performance specifications, etc.) and make note of the desired units
of measure (gallons, liters, etc.).
Press LEFT or RIGHT on the
ARROW KEYPAD to change
the data field.
Trip Planning Data Fields
63
Reference
Active Route Page
Active Route Page
Whenever you have activated a route in the GPSMAP 178/178C, the Active Route Page shows each
point (waypoint or map item) of the active route, with the point name, distance and choice of Course,
ETA, Fuel to point, Leg Distance, Leg Fuel, Leg Time, Sunrise, and Sunset at point location, or Time
To point for each point from your present position. The current destination point, the ‘active’ point, is
marked with an arrow icon. As you navigate a route, the point list automatically updates to indicate the
next ‘active’ point first. The Active Route and Route Review Pages share many of the same features and
options.
Active Route Page Options
Active Route Page
The following options are available by pressing MENU on the Active Route page:
• Edit on Map — see page 61 for instructions.
• Add Before — see page 62 for instructions.
• Remove — see page 62 for instructions.
• Invert — reverses the direction of the route.
To invert an active route:
1 From the Active Route page, press MENU.
2. Using the ARROW KEYPAD, highlight ‘Invert’ and press ENTER to reverse the route.
• Re-evaluate — recalculates and reactivates the current route data. Selects the route leg closest to
your current position as the active leg (the active leg defines the current ‘from’ and ‘to’ waypoints).
To re-evaluate an active route:
1 From the Active Route Page, press MENU.
Active Route Page Menu Options
64
2. Using the ARROW KEYPAD, highlight ‘Re-evaluate’ and press ENTER to recalculate.
Find Key
The FIND key allows you to search the unit for user waypoints, map items, and any optional
BlueChart or MapSource information loaded on a data card. Press the FIND key to search for items from
your current location by default. You may also search from other locations. When you press FIND, a list
of available items to search for appears. The default items are Waypoints, Cities, Tide Stations, and Transportation. Additional items, such as Anchorages, Businesses, Exits, Navaids, Restricted Areas, Wrecks,
Obstructions, etc., are displayed depending on the optional BlueChart or MapSource data card inserted
into the unit. If you pan around on the Map Page and press FIND, the unit centers its search from the
point where the cursor is located. When using BlueChart or MapSource data, your position or the map
pointer must be within the map outline area to search for information from that area.
Reference
Find Key
To find a waypoint or other item from your current location:
1 From any page, press FIND.
2. Using the ARROW KEYPAD, highlight the desired category from the list and press ENTER.
3. For Waypoints and Cities, you may search using ‘By Name’ or’ Nearest’. Use the ARROW KEYPAD
to highlight the desired tab. For ‘By Name’, you may use the top field to spell out the name or scroll
down through the list.
Find Items List From the
Current Location
To find a waypoint or item from another location:
1. Once the search results list is displayed for a particular item, press MENU.
2. Highlight ‘Nearest to Other’ and press ENTER. If you are actively following a route, you may also
choose ‘Nearest to Next’ or ‘Nearest to Destination’.
3. Select a reference point on the map and press ENTER. The search results list changes to list items
nearest to the new map position.
To find a waypoint or item from another location on the map:
1 From the Map Page, use the ARROW KEYPAD to pan to the desired location and press FIND.
2. Using the ARROW KEYPAD, highlight the desired category from the list and press ENTER.
You may also start a ‘Find’ from
items found on the Find List or
from another location on the map.
65
To view details about an item:
Reference
Find Options
Additional Information
Tabs
Distance, Bearing,
Coordinates of item
Additional Option
Buttons
Additional Information Window
1. With the desired item highlighted in the search results list, press ENTER.
2. An Information page appears with details about the item organized in a tabbed format. Depending
on the type of item, additional options are available for viewing the item on the map, viewing notes
on a MapSource or BlueChart map, viewing a tide chart, viewing a list of maps on your data card, and
viewing the next item in the search results list.
The Find option supports a “find from” feature, which allows you to center your search around an
item that you have just found. For example, you search for “Restricted Areas” and the search shows an
“Anchoring Prohibited” search result. If you press FIND again, you see “From Anchoring Prohibited” as
the new search from point. You may also use the Find feature to center your search from any waypoint,
route list entry, map item or tide station. Highlight the item you want to Find ‘from’, and press the FIND
key.
Find Options
Using the Find options, you may search from various map data and utilize variety of nearest
criteria for all items, except waypoints. Available Find options are:
• Nearest To Boat— centers search from your boat’s current location
• Nearest To Other— allows you to choose another map location from which to search.
• Nearest To Next— centers search from the next point of your active route.
• Nearest To Destination— centers search from the last point of your active route.
To find an item using the find options:
1 From any page, press FIND.
Find Menu Options
66
2. Using the ARROW KEYPAD, highlight the desired category from the list and press ENTER.
3 From the search results list, press MENU, then highlight the desired option and press ENTER.
Main Menu Page
Reference
The GPSMAP 178/178C’s Main Menu Page provides access to various waypoint, system, navigation
and interface management, and setup menus in an easy to use “tab” format. The Main Menu Page is
available from any page in the GPSMAP 178/178C’s system, and is accessed through the MENU key. See
pages 2-3 for additional instructions changing settings and entering data.
Main Menu Page
To access the Main Menu Page:
1. Press MENU twice. The 16 Menu tabs are divided into categories by function.
To select a Menu tab from the Main Menu page:
1. Move the ARROW KEYPAD UP or DOWN to highlight the tab you want to view. The information for
the highlighted tab automatically appears to the right. If you want to highlight any of the tab items,
press to the RIGHT on the ARROW KEYPAD, then move UP or DOWN to select individual items.
2. Press either MENU for additional submenu options or press ENTER/MARK to make changes to the
highlighted item. Press LEFT on the ARROW KEYPAD to get back to the Menu tab list. Press QUIT to
return to the Main Menu Page.
Submenu Tabs
Main
Menu
Tabs
The Main Menu tabs are:
•
•
•
•
•
•
•
•
•
•
•
•
GPS – shows satellite status, accuracy, initialize position.
Tide – shows 24 hour tide chart with levels and times.
Trip – provides trip speeds, odometers, averages, and trip timers.
Celes – shows sun/moon time cycles and positions.
Points – allows you to create, edit or delete waypoints. See page 44.
Route – allows you to create, edit, activate or delete routes. See page 57.
Track – lets you record a track, define how it is recorded and displayed.
DSC— allows you to control the Digital Selective Calling (DSC) interface.
Card – interface control for saving waypoints, routes and tracks to a data card.
Map – sets up Map Page features, zooms, and text size. See page 25.
Hiway – sets up Highway Page features. See page 43.
Temp – sets up and shows the water temperature log. (continued)
Main Menu Page
67
•
•
•
•
Reference
Main Menu: GPS Tab
Receiver
Status
Differential
Status
Accuracy
Sky View
Signal
Strength
Bars
Main Menu— GPS Tab
90°
Center dot - 90°
above the horizon
Inner ring- 45°
above the horizon
Outer ring the horizon
45°
68
Sonar – sets up Sonar Page features, speeds and calibrations. See pages 39.
Setup – defines System, Units, and Time settings.
Comm – interface settings for use with a PC or second device.
Alarm – sets up alarms for anchor drag, arrival, off course, and clock.
GPS Tab— provides a visual reference of satellite acquisition, receiver status, and accuracy. The status
information gives you an idea of what the receiver is doing at any given moment. The sky view and signal
strength bars give you an indication of what satellites are visible to the receiver and whether or not they
are being tracked. The signal strength is shown on a bar graph for each satellite, with the satellite number
below. As the receiver locks onto satellites, a signal strength bar appears for each satellite in view. The
progress of satellite acquisition is shown in three stages:
• No signal strength bars— the receiver is looking for the satellites indicated.
• Light/White signal strength bars— the receiver has found the satellite(s) and is collecting data.
• Dark/Green signal strength bars— the receiver has collected the necessary data and the satellite(s)
are ready for use.
As soon as the GPSMAP 178/178C has collected the necessary data from the best satellites in view to
calculate a fix, the status field indicates a 2D or 3D status. The unit then updates the position, date, and
time.
You can use the sky view to help determine if any satellites are being blocked, and whether you have
a current position fix (indicated by a ‘2D’, ‘2D Differential’, ‘3D’, or ‘3D Differential’ in the status field).
The sky view shows a bird’s-eye view of the position of each satellite relative to the receiver’s last known
position. The outer circle represents the horizon (north up), the inner circle 45º above the horizon, and
the center point a position directly overhead. You can also set the sky view to a ‘Track Up’ configuration,
causing the top of the sky view to align along your current track heading.
WAAS Capability
The GPSMAP 178/178C is capable of receiving WAAS (Wide Area Augmentation System) satellite signals. WAAS is an FAA (Federal Aviation Administration) funded project to improve the overall
accuracy and integrity of the GPS signal for aviation use, but land/sea based users may also benefit from
this system. At this time, the system is still in the development stage and is not fully operational. There
are currently two WAAS satellites that can be received in the U.S.A., one over the Atlantic Ocean and
one over the Pacific Ocean, in a geo-stationary orbit over the equator. Effective use of the WAAS satellite
signal may be limited by your geographic location in relation to those satellites, now in developmental
service. WAAS satellite signal reception requires an absolute clear view of the sky and works best when
there are no nearby obstructions such as buildings, mountains, etc. WAAS satellites are numbered 33 or
higher when viewing the sky view on your GPSMAP 178/178C. Initial reception of the WAAS signal may
take up to 15-20 minutes, then 1-2 minutes afterwards. When WAAS differential correction has been
received for GPS satellites (numbers 32 or below), a ‘D’ appears in the signal bar of the sky view and ‘2D
or 3D Differential’ appears in the receiver status. To learn more about the WAAS system, its satellite positions and current state of development, visit the FAA web site (http://gps.faa.gov). Since WAAS requires
CPU resources of the GPSMAP 178/178C to search for and track the satellites, you may disable the
WAAS feature to improve unit performance if WAAS reception is not available in your area.
Reference
Main Menu: GPS Tab
Highlight ‘WAAS Off’ and press ENTER
to disable the WAAS capabilities.
To disable/enable WAAS capability:
1. From the GPS tab, press MENU, then use the ARROW KEYPAD to highlight ‘WAAS Off’ or ‘WAAS
On’ and press ENTER.
Receiver Status and Accuracy
Receiver status is indicated at the top field of the page, with the current Accuracy and Dilution Of
Precision (DOP) to the right of the sky view. Accuracy uses DOP and other factors to calculate horizontal
position accuracy in feet or meters.
69
Reference
Main Menu: GPS Tab
When the GPSMAP 178/178C is using a differential correction signal (either WAAS or DGPS),
a “D” is displayed at the bottom of the signal
strength indicator bars for the satellites that are
corrected.
70
The status field shows one of the following conditions:
• Looking For Satellites – the receiver is looking for any satellites.
• AutoLocate – the receiver is looking for any satellite whose almanac has been collected. This
process can take up to five minutes.
• Acquiring Satellites – the receiver is looking for and collecting data from satellites visible at its last
known or initialized position, but has not collected enough data to calculate a fix.
• 2D – at least three satellites with good geometry have been acquired and a 2 dimensional position
fix (latitude and longitude) is being calculated. ‘2D Differential’ appears when you are receiving
DGPS corrections in 2D mode and a ‘D’ shows on the strength bar of satellites being corrected.
• 3D – at least four satellites with good geometry have been acquired and your position is now being
calculated in latitude, longitude and elevation. ‘3D Differential’ appears when you are receiving
DGPS corrections in 3D mode and a ‘D’ shows on the strength bar of satellites being corrected.
• Poor GPS Coverage – the receiver is no longer tracking enough satellites for a 2D or 3D fix.
• Receiver Not Usable – the receiver is unusable, possibly due to interference or abnormal satellite
conditions. Turn the unit off and back on to reset.
• Simulating – the receiver is in simulator mode.
The Differential Receiver status shows one of the following:
• Off – No optional beacon receiver attached or enabled in the Comm menu or WAAS Off.
• Searching For WAAS – WAAS is enabled and receiver is searching for WAAS signal.
• Using WAAS – WAAS capability enabled and unit receiving WAAS corrections.
• No Beacon Signal – DGPS receiver attached, but not transmitting RTCM data to GPS.
• Tuning Beacon – Receiver is tuning manual DGPS frequency.
• Receiving Beacon – Unit is receiving DGPS corrections.
• Scanning Beacon – DGPS receiver is scanning for available frequency.
• Using DGPS – Indicates a Differential signal is being received (only displays when the Serial Data
Format is set to “Other DGPS” on the Comm Tab of the Main Menu).
The Differential SNR (Signal to Noise Ratio) indicates, on a scale to 0-30db with 30db being the best,
the strength of the DGPS signal being received. The SNR depends upon the mounting of your DGPS
receiver and the distance from the DGPS transmitting station.
The GPS Info tab features an options menu that provides access to functions and features relating to
the GPS Info display.
The following options are available by pressing MENU on the GPS Info Tab of the Main Menu:
• Start/Stop Simulator— toggles the unit simulator on or off. Retail Demo mode restores factory settings to the unit if left unattended for over two minutes. This mode should only be used for display
purposes. User waypoints are NOT deleted.
• WAAS On/WAAS Off— toggles the WAAS capability of the receiver on or off.
• Track Up/North Up— allows you to select between a north up or track up sky view display for the
GPS Info display only.
• AutoLocate— allows the receiver to locate your position automatically. This process can take up to
five minutes.
• Initialize Position— allows you to initialize the receiver graphically on the Map Page to initially
help the receiver acquire more quickly. See page 4 for instructions on initialization.
• Set 2D Elevation— allows you to manually enter the elevation when in 2D or Simulator mode only.
Any elevation entered is automatically calculated when the GPS is in 3D mode.
Reference
Main Menu: GPS Tab
GPS Tab Options Menu
To select a menu option:
1. Using the ARROW KEYPAD, highlight the desired option and press ENTER.

NOTE: If a DGPS receiver is attached to the unit and Garmin DGPS, RTCM In/NMEA Out,
or Other DGPS is enable on Port 2, WAAS is automatically disabled (WAAS Off). It is not
possible for the GPSMAP 178/178C to receive WAAS and DGPS corrections at the same
time.
71
Reference
Station Name
Date
Tide Tab— shows a graphical chart which displays tide station information in a 24 hour span
starting at midnight. You can choose from different dates and over 3000 tide stations around the USA
coastline, Alaska, Hawaii, western Canada and several of the Caribbean islands.
The top of the page displays the tide station being referenced, and the date. The bottom of the chart
shows a 24-hour block of local time for your position. Daylight (light bar or yellow on 178C) and nighttime (dark bar or blue on 178C) show across the time scale, with the time progressing from left to right.
(Local time scales and sunrise/sunset info may not be available for a few stations). The solid, light vertical
lines are in 4-hour increments, and the light, dotted vertical lines are in 1-hour increments. A solid, vertical line (with the current time box at the top) will indicate the time of day when using current date and
will intersect the tide graph to show their relation.
Tide Chart
Event Times
Main Menu—Tide Tab
Max. Level
Current Tide Height Bar
Min. Level
You can select from a list of
nearest stations.
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Low Tide Curve
High Tide Curve
Day
Night
The tide curve shows as a shaded area, with higher tides being taller (blue on 178C) and lower tides
shorter (red on 178C). The solid, horizontal line (with the current tide box on the left) indicates the current tide height. The figure to the left of the line will show the current tide level. The Mean Lower Low
Water (MLLW) appears as a solid, horizontal line near the bottom of the chart (This line will only appear
if the tide ranges to the zero value or below). The numbers on the top and bottom of the left side indicate
the maximum/minimum levels, respectively. The four data fields below the chart, indicate event times
and levels at which the tide changes starting in the upper left field, going downward, then to the upper
right and down again. When comparing with other tide tables, be sure the depth unit value is the same
for both sources.
To select the nearest tide station from your current location:
1. From the “Tide” tab, highlight the ‘At’ field and press ENTER/MARK.
2. Highlight the desired station on the list and press ENTER/MARK twice.
If you are not within this range, you will see a message “None Found”. Use the ‘Nearest To Other’
Find option and select a location closer to a tide station.
Reference
Main Menu: Tide Tab
To select a tide station from the map:
1. Press FIND, select ‘Tide Stations’ and press ENTER/MARK.
2. Press MENU after the search results appear.
3. Highlight ‘Nearest To Other’ and press ENTER/MARK.
4. Select a position on the map and press ENTER/MARK.
5. A list is displayed showing up to nine of the nearest tide stations. Highlight the desired station and
press ENTER/MARK. Select the ‘Show Chart’ button and press ENTER/MARK. If the “None Found”
message appears, repeat steps 1-4 until you find a station.
You may also change the date to see tide charts for other days.
Tide Station List Menu Options
Press MENU on the Tide Station list to access additional
search options. The ‘Nearest to Next’ and ‘Nearest to Destination’ options are enabled when you are actively going to a
destination (following a Go To or a Route, for example). You
must select a location within 100 nm. of a tide station.
To change the date for the tide chart:
1. Using the ARROW KEYPAD, highlight the “On” field and press ENTER/MARK.
2. Enter the desired date and press ENTER/MARK.
To use the current date:
1. Press MENU, then highlight ‘Use Today’s Date’ and press ENTER/MARK.
You may move the time bar on the tide chart in 5 minute increments to show tide heights at various
times on the chart.
To see tide heights at various times on the chart:
1. Move the highlight to the chart.
2. Press LEFT or RIGHT on the ARROW KEYPAD to change the time. Press QUIT when done.
You may move the cursor to see tide heights at different times. Tide data shows in a black box when
in cursor mode.
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Trip Tab— displays Trip Odometer, Moving Average Speed, Total Average Speed, Maximum Speed,
Stopped Time, Moving Time, Total Time, and Odometer.
Reference
To reset the trip data:
Main Menu: Trip Tab/
Celestial Tab
1. Highlight ‘Reset Trip’, ‘Reset Max Speed’, ‘Reset Odometer’, or ‘Reset All’ and press ENTER.
Celes (Celestial) Tab— displays celestial data for sun and moon rise/set, moon phase, and approximate
skyview location of the sun and moon. The moon phase displays the current visible portion of the moon
as a light color. You may display this data for your current position, a position from the map, or a Find
item location. Also, you may select a different date and time, or use the current data.
To choose another position:
1. From the Celestial tab, highlight the ‘At’ field and press ENTER.
2. The Find menu appears. Make a selection and press ENTER until the information for that location is
displayed on the Celestial tab. See pages 65-67 for more information on using the Find feature. List
highlight any category, except Other Location, and press ENTER. If you wish to reference a Find item,
select from the Find list, and press ENTER.
Main Menu— Trip Tab
Date/Time
Position
Sun/Moon
Event Times
Skyview
Window
Moon
Phase
Sun
Position
The location the unit is using appears in the ‘At’ field. The timetables displayed is based upon your
current time zone. You may change your time zone to view times from another zone. Keep in mind this
changes the time settings for the entire unit. (see page 86).
To change the time or date:
1. From the Celestial tab, use the ARROW KEYPAD to highlight the date or time field and press
ENTER.
2. Enter a new date or time and press ENTER.
3. To return to the current date and time, press MENU, use the ARROW KEYPAD to highlight ‘Use
Current Date and Time’ and press ENTER.
To change the skyview orientation:
Overhead (90°)
45°
20°
Horizon (0°)
Main Menu— Celestial Tab
74
1. From the Celestial tab, press MENU, then use the ARROW KEYPAD to highlight ‘North Up’ or ‘Track
Up’ and press ENTER.
Points Tab— contains the ‘User’ and ‘Proximity’ waypoint lists. See page 50.
Route Tab— contains a list of available routes. See page 59.
Track Tab— lets you specify whether or not to record a track log (an electronic ‘breadcrumb trail’
recording of your path), define how it is recorded, or save track log data for future use. The Track Tab
also provides an indicator of the memory used for the active track log and options to clear the track
memory or start a TracBack route. See page 54 for TracBack information. The Track submenu is divided
in two tabs: ‘Active’ tab and the ‘Saved’ tab.
Active Submenu Tab— is for the active log (the log currently being recorded). It displays track memory
used and current settings. For the ‘Active’ tab, the following settings are available:
• Record Mode— lets you select one of three track recording options:
Off— No track log is recorded. Note that selecting the ‘Off’ setting prevents you from using the
TracBack feature.
Fill— a track log is recorded until the track memory is full.
Wrap— A track log is continuously recorded, wrapping through the available memory (replacing the oldest track data with new data).
• Color (178C)— lets you choose a color that is used to display the active track log.
• Style (178)— choose from 17 different track styles used to display the active track log.
• Interval— defines the frequency at which the track plot is recorded. Three interval settings are
available:
Distance— records track based on a user-defined distance between points.
Time— records track plot based on a user-defined time interval.
Resolution— records track plot based upon a user-defined variance from your course over
ground. The resolution option is the default setting and is recommended for the most efficient
use of memory and TracBack performance. The distance value (entered in the value field) is
the maximum error allowed from the true course before recording a track point.
• Value— defines the distance or time used to record the track log.
• Save— allows you to save the current active track log.
• Erase— allows you to clear the active track log currently stored in memory.
Reference
Main Menu: Track Tab
Main Menu— Active Track
Tab
Main Menu— Saved Track
Tab
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Reference
Main Menu: Track Tab
Saved Submenu Tab— manages a list of any saved track logs, allows TracBack activation, map display
of saved logs. The active log stores up to approximately 10,000 track log points, based upon the criteria
specified in the Track settings. Up to 15 track logs may be saved in memory, with up to 700 track log
points in each saved log.
On the ‘Saved’ tab, the following options are available by highlighting a track and pressing MENU:
• Review On Map – displays the saved track log on a Track Map Page.
• Delete Track – deletes highlighted saved track log from memory.
• Delete All – deletes all saved track logs from memory.
To review and edit a track:
1. On the ‘Saved’ Track tab of the Main Menu, highlight the desired track and press ENTER. The Saved
Track window appears.
Reviewing a saved track
2. You may rename the track, choose to show the track on the Map and Highway Pages, delete the
track, or view the track on a map window.
3. To exit, press QUIT or highlight ‘Next’ and press ENTER.
You may also activate a TracBack from any of the saved tracks on this tab.
To activate a TracBack from the ‘Saved’ tab list:
1. Using the ARROW KEYPAD, highlight the track you wish to use for a TracBack and press NAV.
2. The ‘Follow <track name>’ automatically appears highlighted. Press ENTER.
3. Choose either ‘Original’, which navigates you from the end to the start of your trip, or ‘Reverse’,
which navigates you from the start to the end of your trip and press ENTER.
The track name automatically appears when
highlighted on the ‘Saved’ list and NAV is
pressed.
76
DSC Tab— allows to control and set up DSC (Digital Selective Calling) features on the unit.
What is Digital selective calling (DSC)?
Digital Selective Calling (DSC) uses marine VHF radio and Global Positioning System (GPS) technologies to transmit and receive location information. DSC is used by mariners to assist them in two
major areas: Distress Calls and Position Reporting.
An emergency DSC Distress Call allows a vessel in trouble to transmit a substantial amount of
information in a single transmission or “call,” without the need for voice communication. When any
nearby rescuer receives the DSC signal, an alarm sounds and they immediately receive the position of the
caller. The rescuer may then choose to navigate (Go To) the caller’s position to assist or forward the call
on to the Coast Guard. When the Coast Guard receives the call, they can immediately access the caller’s
information (such as who they are and the type of vessel) in their database while they are in transit to the
caller’s position.
A non-emergency DSC Position Report allows mariners to exchange and display the positions of one
another. Once a DSC position is received, the mariner may choose to create a waypoint or to show the
received position on an electronic map.
Any time a vessel receives a DSC call, they can store that location and quickly navigate to that
position using a Go To. This makes DSC a time-saver, especially in an emergency situation. In order to
use DSC, users must first register their VHF radio with the FCC and receive a Maritime Mobile Service
Identity (MMSI) number.
Reference
Main Menu: DSC Tab
DSC Tab
What is A Maritime mobile service identity (MMSI)?
Maritime Mobile Service Identity (MMSI) basically allows a VHF radio to act like a phone. In order
to make a “call” on a phone, you first need a phone number to dial. The 9-digit MMSI number acts like a
phone number when used in a Position Report and as a unique identifier to the Coast Guard when used
in an emergency Distress Call. In order to obtain a Maritime Mobile Service Identity (MMSI) number,
users must register their VHF radio with the FCC (Form 605). Garmin does not supply this number!
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HOW ARE MMSI ASSIGNMENTS OBTAINED?
Reference
Main Menu: DSC Tab
Non-commercial users (e.g. recreational users who remain in domestic waters and only carry VHF,
EPIRB (Emergency Position Indicating Radio Beacons), and Radar) are not required to have a FCC ship
station license. The FCC and Coast Guard have authorized some second and third party vendors to assign MMSI numbers. This service is limited to registering recreational vessels only.
To receive information on how to obtain a recreational MMSI number please contact:
http://www.uscg.mil/rescue21/links/mmsi.htm or http://wireless.fcc.gov/marine/
U.S Non-Federal User: Commercial users, or those who travel outside the U.S. or Canada, must
apply for a ship station license, or an amendment to a ship station license. To find out if you require a
Ship Station license contact: http://wireless.fcc.gov/marine/fctsht14.html If your vessel requires licensing
by the FCC you will obtain a MMSI during the application/licensing process when you file FCC Forms
159 and 605.
U.S. Federal User: Federal users can obtain MMSI assignments from their agency radio spectrum
management office. These procedures are currently under review by the NTIA (National Telecommunications and Information Administration).
Outside the U.S.: Users can obtain an MMSI assignment from their telecommunications authority or
ship registry, often by obtaining or amending their ship station license.
In Canada: Industry Canada is responsible for assigning MMSI numbers to commercial and recreational vessels. Information is available at the following web site: http://apollo.ic.gc.ca/english/mmsi.html
For more information on MMSI’s visit: http://www.navcen.uscg.gov/marcomms/gmdss/mmsi.htm
78
HOW CAN GARMIN HELP YOU WITH DSC?
To receive Distress Calls or Position Reports, you must have a DSC-equipped chartplotter as well as a
VHF radio with DSC support. During normal, non-emergency Position Report communication, Channel
70 (156.525 MHz) has been set aside as the VHF/DSC digital call channel. For a Distress Call, a mariner
presses the MayDay button on their VHF radio. The call transmits on an emergency channel with the
MMSI number attached to the call (if you have DSC support). Any DSC-equipped mariner (on sea or
land) within range can receive the call.
When the Garmin GPSMAP 178/178C is connected to a VHF with DSC support, the GPS unit
displays a Call List, Log, and a Directory available to store incoming information received from another
user’s DSC capable VHF/GPS combination. Basic wiring is required for the Garmin unit and VHF radio
to send and receive NMEA data from each other (see page 96).
DSC Distress Call
With a Garmin DSC capable chartplotter/sounder properly connected to a VHF radio with DSC
output, you may receive any DSC Distress Call within range. A window pops up and a message displays when a Distress Call is received. To notify you a Distress Call has been received, an alarm sounds
(if enabled). The alarm only sounds on a Distress Call, and it does not sound on a Position Report.
Distress Calls are broadcasted to all DSC users in radio range.
Reference
Main Menu: DSC Tab
Distress Call Message
Options available from this screen are:
• Show on Map: If you immediately want to see the caller’s position they select ‘Show on Map’.
• Create Waypoint: If you want to create a waypoint of that position, highlight ‘Create Waypoint’
and press ENTER/MARK.
You also have the ability to input a caller’s name, if it is known. (The caller’s name replaces the
MMSI number as a reference once it is entered.)
DSC Position Report
The Position Report operates similarly to the Distress Call. Remember this type of contact is like a
phone call, but no emergency alarms are set off and the call is specific to the receiver. Position Reports
are not broadcasted to all DSC users.
Position Report Message
79
Reference
Main Menu: DSC Tab
DSC Call List
The DSC Call List displays the current calls received. The GPS can manage up to 50 calls. When
‘calls’ are received, they are updated constantly to give the most current information, even if the unit is
left unattended. Any entry from the Call List can be selected to show an Entry Review.
DSC Log
When DSC calls are received, they are automatically stored in the Log, with the latest call at the top.
The unit may store up to 100 logs. Once 100 logs are received, the oldest log file is removed when a
new call is received. The Log displays information of call Type, Date/Time, Position, and MMSI/Name.
Pressing MENU from this page allows you to ‘Sort By Time’, ‘Sort By Name’, ‘Sort By (Call) Type’, ‘Delete’
(only after highlighting a particular call), and ‘Delete All’.
To Review a Call:
DSC Entry Review
1. From the DSC tab of the Main Menu and the Log or Call List tab highlighted, press DOWN Arrow
Keypad until the call you want to review is highlighted.
2. Press ENTER to select the call.
DSC Entry Review
The DSC Entry Review operates similarly to the Distress Page and Position Report Page. This page
has the additional option to ‘Delete’ the displayed call. From the DSC Entry Review, you can ‘Delete’ the
entry, ‘Show on map’, or ‘Create Waypoint’, and create a name for the entry.
DSC Directory
The DSC Directory acts much like a phone book. A user can save up to 50 contacts. The directory
lists by Name and MMSI number. Pressing MENU from this page allows you to create a ‘New Item’,
‘Delete Item’, or ‘Delete All’.
DSC Log
80
There are two ways to add a new entry into the directory.
To add a new Directory entry:
1. Press Menu, then highlight ‘New Item’ and press ENTER.
2. Or, with the Directory Tab highlighted press the Arrow Keypad DOWN, highlight an empty field and
press ENTER to access the New Directory Item window.
Reference
Main Menu: DSC Tab
The New Directory Item window allows you to input information of a known contact.
To add the MMSI number, Name, or Comment:
1. Press UP/DOWN on the Arrow Keypad to highlight the MMSI, Name, or Comment field.
2. Press ENTER to highlight the first digit on that field.
3. Press UP/DOWN on the Arrow Keypad to enter the numbers/letters.
4. Press LEFT/RIGHT on the Arrow Keypad to move to the next position.
5. Press ENTER to accept the entry.
6. Press UP/DOWN on the Arrow Keypad, highlight the ‘Delete’ button and press ENTER to delete the
entry, or highlight the ‘OK’ button and press ENTER to accept the entry.
Adding a Directory Entry
After creating a New Directory Item entry, the name created is attached to that particular MMSI
number. If you return to the Log, the new name is displayed under the corresponding MMSI number.
Another way to input a name is from the Entry Review Page or the DSC Distress Call or DSC Position
Report Pages. The Name field is only available in the GPS. Names cannot be sent like the MMSI numbers
to other DSC users.
DSC Setup
Garmin chartplotters have the ability to turn DSC ‘On’ or ‘Off’. This option is beneficial for users who
have more than one GPS chartplotter. If you want only DSC to display on a particular chartplotter, turn
DSC off on the remaining Garmin chartplotters that support DSC.
DSC Setup
“Simulate” options only appear while in
Simulator mode.
81
Reference
Main Menu: DSC/Card Tabs
A user also has the ability to simulate a Distress Call or a Position Report on this page. This is helpful
for practice before connecting to the real system. The Distress Call simulator also helps to check if alarms
are working properly.
To run a simulation:
1. Place the chartplotter into simulation (see page 7).
2. From the Main Menu, select the DSC tab, then highlight the Setup tab.
3. Highlight which simulation you wish to run and press ENTER.
Using the NAV Key
The receiver of a Distress Call or Position Report can quickly navigate to the caller using the NAV
button. Once the call is logged, press the NAV button and select to Go To the MMSI number or the Name
of the caller.
Card Tab— interface control for saving waypoints, routes and tracks to a data card.When data is saved
to a data card, it may be exchanged with other compatible units and Garmin’s MapSource PC program.
To transfer data to/from a data card:
1. Insert the data card. If there is already user data on the card, highlight ‘User Card’ and press ENTER.
From the ‘Card’ tab, select the checkbox next to each type of item you want to transfer. You may also
press MENU and choose to ‘Select All’ or ‘Clear All’.
Card Tab
2. Highlight ‘Save To Card’ and press ENTER to save the selected items to the data card.
3. If transferring data from the card to the unit, highlight ‘Merge From Card’ and press ENTER to
combine the selected items with those of your GPS. Highlight ‘Replace From Card’ and press ENTER
to overwrite all selected items on your GPS.
4. A ‘Transfer Complete’ message appears once the data has been transferred. Press ENTER.
82
Map Tab— contains setup options for the Map Page. See page 25.
Reference
Hiway Tab— contains setup options for the Highway Page. See page 43.
Temp (Temperature) Tab— displays the water temperature log (if equipped with a temperature
transducer/sensor). The chart reads from right to left, so that the most recent temperature measured is
displayed on the far right side of the chart. The dotted lines within the chart indicate intervals in the
temperature scale and the duration of time.
The following settings are available:
• Temperature Scale – sets the temperature range (in degrees) for displaying the log. Select ‘Auto’ to
have the unit automatically determine the best range, or select a span of 2, 4, 6, 8, or 10 degrees.
• Time Duration – sets how fast or slow the temperature log scrolls; the shorter the time duration, the
faster the temperature log scroll. Select a duration from 1 minute to 2.5 hours.
Sonar Tab— contains setup options for the Sonar Page. See page 39.
Main Menu: Temp Tab/
Setup Tab
Time
Duration
Temperature
Scale
Setup Tab— consists of three submenu tabs; System, Units, and Time.
System Submenu Tab— controls system settings for beeper, speed filter, languages, system mode,
simulator controls, restores factory settings, and displays software version.
The following settings and options are available:
• Beeper – controls audible beep. Select from ‘Off’, ‘Alarms Only’ (sounds for alarms/messages), or
‘Key and Alarm’ (sounds for key presses and alarms/messages).
• Speed Filter – averages speed-readings. Choose from ‘Off’, ‘Auto’ (automatically controls filtering),
or ‘On’ (allows you to enter a value from 1 to 255 seconds).
• Language – select from various languages for the unit’s on-screen display.
• System Mode – select from ‘Normal’ (Normal Navigation) or ‘Simulator’ (For practice ONLY),
Sounder Only, or GPS Only.
Set Position* – allows to set your location while in simulator mode. See page 11, starting with
step 2, for additional instructions.
Main Menu—Temp Tab
Main Menu—System Tab
(Normal Mode)
83
Reference
Main Menu: System Tab/
Units Tab
Track Control* – ‘Auto Track’ steers to the current navigation point. ‘User Track’ allows you to
enter a heading in the ‘Track’ field.
Track* – lets you enter a heading.
Speed* – lets you enter a speed.
Transducer* – lets you simulate using a Depth Only, Temp Only, or Temp/Speed transducer.
* These fields only appear when the unit is in Simulator Mode.
• System Information – displays the unit’s software, basemap version, and electronic serial number.
Press MENU for the following options:
• Defaults – restores settings on System page to default values.
• All Unit Defaults – restores all settings to Garmin’s original setup values for the entire unit.
Units SubmenuTab— defines settings for Position Format, Map Datum, Heading, Distance, Speed,
Elevation, Depth, and Temperature.
Main Menu—System Tab
(Simulator Mode)
Main Menu—Units Tab
84
The following settings are available:
• Position Format – is used to change the coordinate system in which a given position reading is
displayed. You should only change the position format if you are using a map or chart that specifies a different position format or wish to use a format you are familiar with. The default format is
latitude and longitude in degrees, minutes, and thousandths of a minute (hddd°mm.mmm’). The
following additional formats are available:
• hddd.ddddd° – latitude/longitude in decimal degrees only
• hddd°mm’ss.s” – latitude/longitude in degrees, minutes, seconds
• UTM/UPS – Universal Transverse Mercator / Universal Polar Stereographic grids
• British Grid
• Dutch Grid
• Finnish KKJ27
• German Grid
• India Zones
• Irish Grid
• Loran TD
• Maidenhead
• MGRS
• New Zealand
• Qatar Grid
• RT90
• Swedish Grid
• Swiss Grid
• Taiwan Grid
• User Grid
• W Malayan RSO • UTM/UPS
For additional information on Loran TD setup, see page 102.
• Map Datum – allows you to manually select the datum reference used to determine a given position. The default setting is ‘WGS 84’. The unit automatically chooses the best datum depending
upon your chosen position format. Datums are used to describe geographic positions for surveying,
mapping, and navigation and are not actual maps built in the unit. Although over 100 datums are
available (as listed on page 104), you should only change the datum if you are using a map or chart
that specifies a different datum.

WARNING: Selecting the wrong map datum can result in substantial position errors.
• Heading – lets you select the reference used in calculating heading information. You can select from
‘Auto Mag Var’, ‘True’, ‘Grid’, and ‘User Mag Var’. ‘Auto Mag Var’ provides magnetic north heading
references which are automatically determined from your current position. ‘True’ provides headings
based upon a true north reference. ‘Grid’ provides headings based on a grid north reference (and
is used in conjunction with the grid position formats described on page 84). ‘User Mag Var’ allows
you to specify the magnetic variation at your current position and provides magnetic north heading
references based upon the variation you enter.
To enter a user defined magnetic variation:
1. With the Heading field set to ‘User Mag Var’, highlight the heading reference field (immediately to the
right) and press ENTER.
2. Use the ARROW KEYPAD to enter the magnetic variation at your current position and press
ENTER.
• Distance, Speed, and Elevation – lets you select the desired units of measure for distance, speed and
elevation readouts in ‘Nautical’ (nm, kt, ft), ‘Nautical’ (nm, kt, m), ‘Statute’ (mi, mh, ft), or ‘Metric’
(km, kh, m) terms.
• Depth – lets you select the desired units of measure for depth in Feet (ft), Fathoms (fa), or Meters (m).
• Temperature – lets you select the desired units of measure for temperature in Fahrenheit (°F) or
Celsius (°C).
Reference
Main Menu: Units Tab

The Units tab settings affect how navigation information is
displayed on the GPSMAP 178/178C. When in doubt, seek
assistance.
If you are using a map or chart in conjunction with your
GPS, make sure the settings under the ‘Units’ tab of the
GPSMAP 178/178C match that of the map or chart. This
information should be displayed somewhere on the map or
chart. If the information is not present, contact the map or
chart maker to determine what position format, datum,
heading and units of measure are being used for the map
or chart.

WARNING: If ‘User Mag Var’ is selected, you must
periodically update the magnetic variation as your position
changes. Using this setting, the unit does not automatically calculate and update the magnetic variation at your
present position. Failure to update this setting may result in
substantial differences between the information displayed
on your unit and external references, such as a magnetic
compass.
85
Reference
Main Menu: Time/
Comm Tab
Time Submenu Tab— displays the current time and date, allows you to adjust the 12 or 24-hour
time format, enter a time zone, and adjust for daylight savings to show correct local time.
The following options are available:
• Time Format – 12 hour, 24-hour (military) or UTC time (also called Greenwich Time).
• Time Zone – choose your time zone to show correct local time or choose ‘Other’ and enter a UTC
Offset. The UTC offset is how many hours you are ahead or behind the time line. See the table on
page 96 for time offsets.
• Daylight Savings – choose from ‘Auto’, ‘On’, or ‘Off’ to adjust for daylight savings.
Comm (Communications) Tab— lets you control the input/output format used when connecting your
GPSMAP 178/178C to external NMEA devices, a DGPS beacon receiver, a personal computer, another
Garmin GPSMAP 178/178C, etc. If a DGPS receiver is used, WAAS capability is automatically turned to
‘Off’. The unit supports two input/output ports. See page 96 for more information on wiring and NMEA
information. Individual Port settings are:
Main Menu—Time Tab
Main Menu—Comm Tab
Data Transfer Progress
86
Port 1:
• Garmin Data Transfer – the proprietary format used to upload/download MapSource data,
exchange waypoint, route, track, almanac, and proximity data with a PC or another Garmin
GPSMAP 178/178C. When you select ‘Garmin Data Transfer’, there are 11 Transfer Modes to
choose from: Host, Request Almanac, Request Proximity, Request Routes, Request Tracks, Request
Waypoints, Send Almanac, Send Proximity, Send Routes, Send Tracks, and Send Waypoints.
• NMEA In/NMEA Out – supports the input/output of standard NMEA 0183 data and DSC.
• None – provides no interfacing capabilities.
Port 2:
• Garmin DGPS – used to connect the GPSMAP 178/178C with a Garmin DGPS beacon receiver.
• Other DGPS – allows DGPS input using a standard RTCM format, without any output capabilities.
• NMEA In/NMEA Out – supports the input/output of standard NMEA 0183 data and DSC. You
may also adjust the NMEA output.
• RTCM In/NMEA Out – allows Differential GPS (DGPS) input using a standard RTCM format and
also provides NMEA 0183 output.
• None – provides no interfacing capabilities.
Reference
Main Menu: Comm Tab
To select an input/output format:
1. Select the desired Port tab, then highlight the ‘Serial Data Format’ field and press ENTER.
2. Use the ARROW KEYPAD elect the desired setting and press ENTER.
To select a transfer mode:
1. Use the ARROW KEYPAD to select ‘Garmin Data Transfer’ in the ‘Serial Data Format’ field.
2. Highlight the ‘Transfer Mode’ field and press ENTER.
3. Use the ARROW KEYPAD to select the desired setting and press ENTER.
You may also adjust the NMEA output to enable/disable certain sentences and adjust the number of
Lat/Lon output precision digits. You must have one of the ports set to NMEA In/NMEA Out to use this
option. Settings affects both Port 1 and Port 2 NMEA outputs.
When transferring data between two Garmin units,
be sure to always set one to ‘Host’ and use the other
unit to either Send or Request the desired data.
87
To restore the Serial Data Format settings to the default ‘Garmin Data Transfer’:
Reference
1. From the Comm tab, press MENU, highlight ‘Defaults’ and press ENTER.
Main Menu: Comm Tab
Status Field
If ‘Garmin DGPS’ or ‘RTCM In/NMEA Out’ format is selected, additional fields are provided to control a Garmin differential beacon receiver directly from your GPSMAP 178/178C. You may have the unit
automatically scan for the DGPS beacon signal or you can enter the beacon frequency and bit rate on the
unit and the information is used to tune the beacon receiver.
To have the unit automatically scan for a frequency:
1. With the unit set to ‘Garmin DGPS’ or ‘RTCM In/NMEA Out’, use the ARROW KEYPAD to highlight
the “Beacon” field and press ENTER.
2. Highlight ‘Scan’ and press ENTER. The numbers in the ‘Frequency’ field changes as the unit scans
from 284 kHz to 325 kHz, 200 bit rate, then 100, at 6-second intervals.
SNR and Distance shows data
when signal is received.
To restart the scan:
1. Press MENU, highlight ‘Restart Scan’ and press ENTER. The “Status” field shows one of the
•
•
•
•
following:
Tuning – unit is attempting to tune to the specified frequency and bit rate.
Scanning – unit is automatically scanning through the frequencies and bit rates.
Receiving – unit is receiving DGPS signal and ready for operation.
Check Wiring – unit is not making connection with DGPS receiver.
When the unit is receiving a DGPS signal, the “SNR” (Signal to Noise Ratio) and “Distance” fields
shows data. The SNR range is 0dB to 30dB, with 30 being the best. The Distance may or may not show
data, depending upon the signal being broadcast from the DGPS site.
You may also manually enter a
frequency and bit rate.
88
The DGPS beacon transmitters are operated by the U.S. Coast Guard (or similar government agency
in other countries), which is responsible for their accuracy and maintenance. For DGPS transmitter
problems or to find the most updated list of frequencies and coverage areas, contact your local USCG, or
see their web site at http://www.navcen.uscg.mil/
NMEA Interface
If you are going to interface the GPSMAP 178/178C with another piece of equipment (such as a radio
or autopilot), the unit needs to be set to output NMEA data. More information on wiring and NMEA data
may be found on page 96.
Reference
Main Menu: Comm Tab
To activate the NMEA data:
1. On either port of the Comm Tab, highlight the ‘Serial Data Format’ field and press ENTER.
2. Select ‘NMEA In/NMEA Out’ and press ENTER.
Advanced NMEA Output Setup
The GPSMAP 178/178C NMEA data transmission can be customized to change the precision of the
Lat/Lon minutes, set up the waypoint IDs, and keep the output rate at two seconds. If the unit is set up
to output all of the available NMEA sentences, the output rate may exceed two seconds. The ‘Advanced
NMEA Output Setup’ Page allows you to turn on/off the GPS status (GSA. GSV), Waypoint/Route (WPL,
RTE), and the Garmin Proprietary sentences. See page 96 for more information on wiring and NMEA
data.
Lat/Lon Minutes Precision allows you to adjust the number of digits to the right of the decimal point
for transmission of NMEA Output, either 2, 3, or 4 digits. The Waypoint ID setting lets you choose to
output the waypoint identifiers as names or numbers.
Activating NMEA data
To set up the Advanced NMEA page:
1. Highlight ‘NMEA In/NMEA Out’ in the Serial Data Format field, and press MENU. Select ‘NMEA
Setup’ and press ENTER.
2. To change the settings, place the highlight over the desired field and press ENTER. Make a
selection and press ENTER again to accept the selection.
89
Reference
Main Menu: Comm Tab/
Alarm Tab
GPSMAP 178/178C NMEA Sentence Output (NMEA version 3.01 compliant)
Always transmitted: GPRMC, GPGGA, GPGLL, GPBWC, GPVTG, GPXTE, GPRMB, SDDBT,
SDDPT, SDMTW, SDVHW
Switchable sentences: GPGSA, GPGSV, GPWPL, GPRTE
Garmin proprietary: PGRME, PGRMZ, PGRMM
Alarm Tab— contains setting for the unit’s alarms. The Alarm tab is divided into three submenus:
System alarms, Nav alarms, and Sonar alarms.
System Submenu Tab
Advanced NMEA
Setup Page
Clock – provides an alarm for the system clock. Enter a time in the time field and turn the alarm
on and off from the control field menu. Remember to enter alarm times in the same time format
(UTC or local) you’re using for your system. The unit must be on for the clock alarm to work.
Battery – sets an alarm to sound when the battery is reaching a critical state of discharge.
DGPS – sets an alarm to sound when the unit loses a differential fix.
Accuracy – sets an alarm to sound when the GPS position accuracy falls outside the user-set
value.
Nav Submenu Tab
Main Menu—Alarm Tab
(System Submenu)
90
Anchor Drag – sets an alarm to sound when you’ve exceeded a specified drift distance. Enter a
value in the distance field and use the control field to turn the alarm on and off.
Arrival – sets an alarm to sound when you’re a specified distance or time away from a destination
waypoint. Enter a distance radius or time for sounding the alarm and use the control field to set
the alarm to ‘Off’, ‘Dist’ (Distance), or ‘Time’.
Off Course – sets an alarm to sound when you’re off a desired course by a specified distance.
Enter a distance in the distance field and use the control field to turn the off course alarm on and
off.
Sonar Submenu Tab
Shallow Water/Deep Water – set alarms to sound when you enter an area of specified depth that
is too shallow and/or too deep. You must be receiving sonar data for this function to work.
Water Temperature – sets an alarm to sound when the transducer reports a temperature either
above, below, inside or outside the specified values.
Fish – sets an alarm to sound when the unit detects a fish of the specified size symbol(s).
Reference
Main Menu: Alarm Tab
To set an alarm:
1. Use the ARROW KEYPAD to highlight desired submenu tab of the Alarm Tab.
2. Highlight the field below the alarm name you wish activate and press ENTER.
3. Change the mode to the desired setting and press ENTER.
4. Highlight the next field to the right and press ENTER, then enter the desired settings and press
ENTER to finish.
5. If you want the alarm to display and beep until acknowledged, highlight the ‘Persist’ box and press
ENTER to place a check mark in the box.
Main Menu—Alarm Tab
(Nav Submenu)
Main Menu—Alarm Tab
(Sonar Submenu)
91
Appendix A
Antenna Installation
Installing the GPSMAP 178/178C
The GPSMAP 178/178C must be properly installed according to the following instructions to get the
best possible performance. To complete the installation, you’ll need the appropriate fasteners and a 1”
x 14-thread marine antenna mount available at most marine dealers. (If you have a GPSMAP 178/178C
with an internal antenna, skip to the next page.) When in doubt, seek professional assistance.
Mounting the GPS Antenna
Suggested locations for mounting the GA 29 antenna.
The antenna should be mounted in a location that has a clear, unobstructed view of the sky in all
directions to ensure the best reception. Avoid mounting the antenna where it is shaded by the boat’s
superstructure, a radome antenna, or mast. Keep the antenna away from the path of a radar’s beam.
Sailboat users should avoid mounting the antenna high on the mast to prevent inaccurate speed readings
caused by excessive heeling. Most marine VHF and LORAN antennas do not seriously degrade the GPS
antenna’s reception. Never paint the antenna or clean it with harsh solvents.
The Garmin antenna screws directly onto any standard 1” x 14-thread antenna mount. If you need
to raise the antenna to avoid shading, try using a 1” x 14-thread extension mast available at most marine
dealers.
To install the GPS antenna:
1. Screw the antenna directly onto the 1” x 14-thread mount.
It is possible to route the coaxial cable either through or
outside the antenna mount. It is possible to remove the BNC
connector on the coaxial cable and shorten the coaxial cable
to ease installation, however, doing so voids the antenna
warranty. If the BNC connector is removed it must be
replaced with a new solder-on or crimp BNC (RG 58 or 59
compatible) connector.
92
2. Route the cable to the mounting location of the display unit. Use appropriate tie-wraps, fasteners, and
sealant to secure the cable along the route and through any bulkhead or deck.
3. Once the GPSMAP 178/178C unit has been installed, connect the cable to the antenna connector on
the back of the display unit. Make sure that you turn the antenna cable connector 1/4 turn clockwise
to lock the cable into place.
Mounting the GPSMAP 178/178C Unit
The GPSMAP 178/178C’s compact, waterproof case is suitable for mounting in exposed locations or
at the nav station. The unit comes with a gimbal bracket that can be used for surface or overhead mounting. When choosing a location for the display unit, make sure you consider the following conditions:
• There should be at least a 3” (5 cm) clearance behind the case to allow connection of the antenna
(external antenna only), power/data cables.
• The mounting surface should be heavy enough to support the unit and protect it from excessive
vibration and shock.
• For GPSMAP 178/178C with a built-in internal antenna, it should be mounted in a location that
has the clearest, most unobstructed view of the sky in all directions to ensure the best reception.
Avoid mounting the unit where it is blocked by the boat’s superstructure, a radar arch, or mast.

Appendix A
Unit Installation
NOTE: The temperature range for the GPSMAP 178/178C is 5°F to 158°F
(-15°C to 55°C). Extended exposure to temperatures exceeding this range (in storage or
operating conditions) may cause failure of the LCD screen. This type of failure and related
consequences are NOT covered by the manufacturer’s limited warranty.
To swivel mount the GPSMAP 178/178C display:
Tools (not included) — Drill, Screwdriver (Phillips or Standard), three #8 (4mm) pan head machine
bolts with matching nuts and washers and a 5/32” (5mm) drill bit, OR three #8 pan head self-tapping
screws and an appropriately-sized drill bit for drilling starter holes. Always wear safety goggles, ear
protection, and a dust mask when drilling, cutting, or sanding.
1. Using the swivel base as a template, mark the location of the three holes that are used to secure
the bracket to the mounting surface.
2. If securing the base with machine bolts, drill three 5/32” (5mm) holes at the locations you marked.
OR, if securing the base with self-tapping screws, drill starter holes at the locations you marked.
Starter holes should generally be no deeper than half the screw length.
3. Secure the swivel base with three bolts or screws. DO NOT OVERTIGHTEN.
4. Place the rest of the mount over the swivel base and secure with the short knob.
Secure the base and attach the mount
OK
The swivel base is designed to be secured using a pan
head screw or machine bolt. If you use a screw with a
countersunk head, you risk damaging the Mounting
Base.
93
Installing the Unit on the Mounting Bracket
Appendix A
Unit Installation
1. Align the slot on the back of the unit with the long mounting knob and slide in place. It may be
necessary to adjust the long mounting knob to spread the bracket arms apart. Turn counter-clockwise
to widen the bracket arms, clockwise to tighten.
2. Adjust the unit angle and tighten the long mounting knob until snug.
3. To tilt the unit, loosen the long mounting knob on the right side of the bracket assembly.
4. To rotate the entire bracket, twist it left or right. The bracket clicks as you turn it.
5. Tighten all knobs once the desired viewing angle is obtained.
Slide the unit onto the bracket
94
Adjust for optimal viewing
Flush Mounting the GPSMAP 178/178C External Antenna Unit
The GPSMAP 178/178C External Antenna only can be flush mounted on a flat panel. When flush
mounting the GPSMAP 178/178C, be sure to choose an appropriately sized location for the unit. Check
that all cables reach the unit mounting location before beginning installation. Use the Flush Mount Template provided in the box to determine a location. Always wear safety goggles, ear protection, and a dust
mask when drilling, cutting, or sanding.
Appendix A
Unit Installation
To flush mount the GPSMAP 178/178C (External Antenna ONLY):
Included Mounting Hardware — 4 - 3mm Studs, 4 - Flat Washers, 8 - 3mm Hex Nuts.
Tools (not included) — Center Punch, Drill, 1/8” (3mm) Drill Bit, 3/8” (6mm) Drill Bit, Jig Saw, 1/16”
(2mm) Allen Wrench, 9/35” (7mm) Wrench.
1. Trim the Flush Mount Template and tape in the desired location.
2. Using a Center Punch, indent the center of each Mounting Hole location.
3. Using a 1/8” (3mm) drill bit, drill the four Mounting Holes.
Hex Nuts
Washer
4. Using a 3/8” (6mm) drill bit, drill a hole for a location to begin cutting the mounting surface.
5. Using the Jig Saw, cut the mounting surface along the inside of the dashed line indicated on the template. Be very careful when cutting this hole, there is only a small amount of clearance
between the unit and the Mounting Holes. It may be prudent to cut slightly inside the indicated
line and then sand or file the panel as needed to obtain the best fit.
Studs
6. Install the four Mounting Studs into the unit by screwing the shorter section into the back of the unit.
Use a 1/16” (2mm) Allen Wrench to tighten the Mounting Studs until the stops contact the case. Be
careful not to overtighten as this may damage the Mounting Stud. The studs have a reusable threadlocking patch pre-applied from the factory.
7. Place the unit in position inside the cutout area of the mounting surface.
8. Place washers over the Mounting Studs, then thread on one Hex Nut per Mounting Stud. Tighten all
four Hex Nuts until the unit is snug against the mounting surface. Install and tighten the second Hex
Nut on all four Mounting Studs to lock the first Hex Nut in place.
95
Appendix A
Wiring and Interfacing
You can download a copy of Garmin's proprietary communication protocol from the Help
and Support section of our web site at www.
garmin.com
Connecting the Power/Data Cable
The power/data cable connects the GPSMAP 178/178C to 10-35 volt DC system and provides
interface capabilities for connecting external devices. The color code in the diagram below indicates the
appropriate harness connections.
To Transducer
Note: During a typical installation,
only the Red and Black wires are used.
The other wires do not have to be connected for normal operation of the unit.
Replacement fuse: AGC/3AG - 2.0 Amp
(red) + 10-35 VDC
(black) - Ground (Power/Data)
To Unit
Complete information concerning
NMEA & RTCM formats and
sentences is available for purchase
from NMEA at:
NMEA
Seven Riggs Avenue
Severna Park, MD 21146
U.S.A.
410-975-9425
410-975-9450 FAX
www.nmea.org
Radio Technical Commission For
Maritime Services (RTCM)
1800 Diagonal Road, Suite 600
Alexandria, VA 22314-2480
U.S.A.
703-684-4481 (Info Only)
703-836-4229 FAX
www.rtcm.org
96
(blue) Port 1 Data OUT
DC �
Power Source
(brown) Port 1 Data IN
RXD +
Pin 11 - Yellow (Alarm)
Pin 14 - Green (TX COM 2)
(white) Port 2 Data IN
Autopilot/
NMEA Device
RXD -
(green) Port 2 Data OUT
Pin 15 - Red (DC Positive)
Pin 13 - White (RX COM 2)
(yellow) Alarm Low
Pin 18 - Black (Ground)
Pin 17 - Blue (TX COM 1)
(Cable View)
Pin 16 - Brown (RX COM 1)
Alarm Relay
100ma max
coil current
TX+
Beacon
Receiver or
DSC VHF
RX+
Interfacing
The following formats are supported for connection of external devices: Garmin proprietary Differential GPS (DGPS), NMEA 0183 version 3.01, RTCM SC-104 input (version 2.0).
The following are the sentences for NMEA 0183, version 3.01 output:
Approved sentences— GPBWC, GPRMC, GPGGA, GPGSA, GPGSV, GPGLL, GPBOD, GPRMB, GPRTE,
GPVTG, GPWPL and GPXTE. Sonar— SBDDBT, SDDPT, SDMTW, and SDVHW Proprietary sentences—
PGRME, PGRMZ, and PSLIB.
Transducers
The transducer acts as the eyes and ears of your new sonar. Proper transducer selection and installation are critical to the operation of your unit. The transducer transmits sound waves toward the bottom
in a cone shape. The larger the cone angle, the larger the coverage area at a given depth.
Appendix A
Selecting a Transducer
A wide cone angle transducer works best in shallow water. The wide cone angle provides a large
coverage area, but at a decreased bottom resolution. In deeper water this can result in a large dead zone
where fish cannot be seen. A narrow cone angle transducer is better suited to deep-water installations.
The narrow cone angle provides a smaller viewing area (compared to a wide cone angle transducer at the
same depth) with improved bottom resolution and a smaller dead zone. Dual frequency transducers give
you the best of both wide and narrow cone angles.
The GPSMAP 178/178C is packaged with and without a transducer. Depending on which transducer
you select, you will have either single or dual frequency performance. Since many mounting locations
vary, there are a variety of standard and optional transducers, and accessories which are available. See
your local Garmin dealer or contact Garmin to help you in your selection of optional transducers and
accessories.
Wide cone angle
Narrow cone angle
dead zone
fish not seen
X
X
97
Appendix A
Mounting the Transducer

DO NOT mount the transducer behind strakes, struts,
fittings, water intake or discharge ports, or anything that
creates air bubbles, or causes the water to become turbulent.
It is important that the transducer be in clean (non-turbulent) water for optimal performance.
Proper transducer installation is key to getting the best performance from your new unit. If the
transducer lead is too short, extension cables are available from your Garmin dealer. DO NOT cut the
transducer lead or any part of the transducer cable, as this voids your warranty. The cable cannot be
spliced and connected to any existing (Garmin or non-Garmin) transducer cables.
Following are some tips and basic installation instructions for some popular transducers. Detailed
installation instructions are provided in the transducer kits. Some transducers may need to be installed
by a professional marine installer.
Transom Mount Installation
Transom Mount Transducer (depth/temp)
To Unit
Apply marine sealant to all
screw threads to prevent water
from seeping into the transom.
Mount the transducer cable cover
well above the waterline.
Transducer should extend 1/8" (3mm) below
fiberglass hull or 3/8" (10mm) below aluminum hull
Speed
Temp
Transducer
OK
Additional Sensor Installation
Make sure that the transducer is
below water level when the boat
is on plane at high speed
Do not mount transducer directly in the
path of the prop. The transducer can cause
cavitation that may degrade the boat's performance
and damage the prop.
98
Mount the transducer parallel with the bottom.
To avoid drilling a hole to mount a thru-hull transducer, a transom mount transducer may be used
with epoxy inside a boat (“shoot-thru-hull” installation). For a transducer to be mounted inside the hull
(shoot-thru, not thru-hull), the boat must be fiberglass, no core (contact your boat manufacturer if you
are unsure). Test by placing a small amount of water inside the hull, placing the transducer on top of the
water, then verifying the accuracy of the locators versus the current water depth. If they are the same, use
slow-curing epoxy (non-silicone based) to affix the transducer to the inside of the hull.
Appendix A
Mounting the Transducer
Shoot-Thru-Hull Installation
The transducer is designed to be mounted inside a fiberglass hull. The standard plastic transom
mount transducer can also be mounted in this fashion using this method. If using a temperature sensing
transducer, the temperature displayed reflects the hull temperature.
PVC Pipe
or a Can
Selecting a location:
1. The location has to be solid fiberglass, devoid of any air bubbles, laminates, fillers, or dead air space.
The location needs to be in an area of clean water at all speeds. Do not place the transducer over any
strakes or behind any obstruction on the hull that would create turbulence at speed.

NOTE: Many modern hulls have a prelocated pocket for shoot-thru-hull transducer
installation. If you are unsure if your hull is equipped with a pre-located pocket,
contact your hull manufacturer.
Testing the location:
Weight transducer
to hold it in place
Fill Pipe or Can
with water or a
light mineral oil
Strip Caulk
or RTV Sealer
Hull Surface
Testing the Location
1. Place the transducer in the water, pointed directly at the bottom and set unit for optimum performance. Place the transducer in the test device as show on the side bar. If the sonar performance is
significantly degraded, another location needs to be tested.
Installing the transducer:
1. Lightly sand the surface of the hull and face of the transducer with 400 grit wet or dry sandpaper.
2. Build a dam using strip caulk about 1/4” tall. Pour about 1/8” of two part, slow cure epoxy in the
dam. Place the transducer in the epoxy, turning the transducer to work out any air bubbles.
3. Weight the transducer in place and allow to cure for 24 hours.
99
Testing the Installation
Appendix A
Testing the Installation
While it is possible to perform some checks with the boat trailered, the boat should be in the water
to properly test the sonar portion of the installation.
Press the POWER button and the GPSMAP 178/178C should power on. If the unit fails to power
on, verify that the wiring adapter is seated properly in the back of the unit, the Red and Black wires are
connected to the correct polarity, and that the fuse is installed and not blown. If the unit is connected to a
power supply that exceeds 35 VDC, a “Battery Voltage High” warning is displayed and the unit turns off.
Since water is necessary to carry the sounder’s sonar signal, the transducer must be in the water to
work properly. It is not possible to get a depth/distance reading when out of the water. As the unit powers
on, it should immediately start showing the bottom. Verify that the unit is not in the simulator mode. If
the unit is in the simulator mode, make sure that the transducer is connected to the wiring harness.
To test the transducer installation, gradually increase the boat speed while checking the unit operation. If the unit displays intermittently or fails to display, verify that the transducer is aligned parallel
with the bottom and if necessary, adjust the transducer height until the unit operates correctly. It may be
necessary to make several adjustments to ensure proper operation throughout the speed range.

100
NOTE: When adjusting the depth of the transducer, make the adjustments in small increments. Placing the transducer too deep can adversely affect the boat’s performance and
put the transducer at greater risk of striking underwater objects.
Installing and Removing Data Cards
The GPSMAP 178/178C uses optional Garmin marine BlueChart and MapSource data cards to
display digital charts and maps on-screen. You may also transfer user data to data cards (pg 82). Data
cards are installed in the card slot located at the bottom right of the unit. Data cards may be installed or
removed at any time, whether the unit is on or off.
Appendix A
Installing and Removing
Data Cards
To install a data card:
1. Open the card door by pressing together on the two handles at the bottom of the door and lifting it
up and open.
2. Insert the card into the slot, with the label facing top and the handle towards you.
3. Firmly push the card into the unit. It in not necessary to force the card and about 1/2” is still exposed
when it is properly inserted. If the unit is on, a confirmation tone sounds and a message displays on
the screen noting the card details when the card has been properly installed and accepted.
4. Close the cover.
If you insert a data card and get a ‘card format not recognized’ message, try removing the card and
reinserting it. If the card is still not recognized, contact the Garmin or your Garmin dealer for assistance.
Data cards are not waterproof, should not be exposed to moisture or excessive static charges, and should
be stored in the case supplied with the card.
To remove a data card:
1. Open the card door by pressing together on the two handles at the bottom of the door and lifting it
up and open.
The first time you insert a
data card, the unit takes
a few seconds to read the
card.
2. Grasp the card handle and pull out firmly.
3. If the unit is on, a confirmation tone sounds when the data card has been removed.
Once the data card has
been read, a summary
screen appears. Press
ENTER to acknowledge.
101
Appendix B
Loran TD
Loran TD System
LORAN-C is a radio navigation aid operated and maintained in the United States by the United States
Coast Guard. The name LORAN is an acronym for “LOng RAnge Navigation”. The LORAN system covers
the entire United States and the U.S. Coastal Confluence Zone. From the perspective of a mariner, the
system is used for ocean and coastal navigation. It can be used as a supplemental system for harbor and
harbor approach navigation, and it is used for inland navigation by recreational vehicles.
LORAN TD Feature
On the Units Tab of the Main Menu, press
MENU, then highlight ‘Loran TD On’ and
press ENTER to select Loran TD.
The LORAN TD (Time Delay) feature eases the transition from using LORAN to using GPS. The
GPSMAP unit automatically converts GPS coordinates to LORAN TDs for those who have a collection of
LORAN fixes for favorite fishing spots and other waypoints recorded as TDs. You can display your position as a TD or enter waypoints as TDs. The accuracy to be expected from this conversion is approximately thirty meters. When the unit is placed in the LORAN TD format mode, it simulates the operation
of a LORAN receiver. Position coordinates may be displayed as TDs, and all navigation functions may be
used as if the unit was actually receiving LORAN signals.
Using the LORAN TD Format
Or, highlight the Position Format field,
highlight ‘Loran TD’ and press ENTER to
select Loran TD.
102
When creating new waypoints using LORAN TD coordinates, you must set the correct LORAN chain
number and secondary stations in the Setup TD field before storing the waypoint. You must have the
correct chain number as well as the secondary station identifiers to use this option correctly. These values
vary per coordinate set or geographical location. Failure to enter correct information could result in
inaccuracies for the desired destination. After the waypoint is stored in unit memory, it always references
the LORAN chain number and secondary stations currently selected in the Setup TD field. If you enter a
different LORAN chain number, change the secondary stations or offsets in the Setup TD field, the active
waypoint information reflects those changes. Since the GPSMAP unit does not rely on the LORAN signal
for navigation, it can reference a different GRI chain and/or secondary stations and still navigate to the
location stored in memory.
The ‘LORAN TD Setup’ window contains the fields to select the Loran GRI-Chain Number, Primary
and Secondary Stations, and TD Offsets.
To setup Loran TD from the Main Menu:
1. Using the ARROW KEYPAD, highlight the ‘Setup tab, then press RIGHT to highlight the ‘Units’ submenu tab. Highlight the “Position Format” field and press ENTER. You may also press MENU from
the “Units” tab to display the ‘Loran TD On’ option. (If you use ‘Loran TD On’, skip to step 3.)
Appendix B
Loran TD Setup
2. Highlight ‘Loran TD’, press ENTER, then highlight ‘Setup’ and press ENTER.
3. To change the settings of any of the five fields, highlight the field, press ENTER, select/enter the
desired setting and press ENTER.
4. When done, press the QUIT key to return to the Main Menu.
If the active GRI Chain, secondary stations or offsets have been changed since the waypoint was
created, the waypoint now references the active GRI-chain and secondary stations and adjust the TD
coordinates accordingly. Remember that the GPS is not relying on the LORAN signal for navigation and
actually converts the TD coordinate to a useful LAT/LON coordinate (in the background) before storing
the waypoint to memory or using it for navigation. Because of this the unit can navigate to a TD coordinate anywhere in the world.
Loran TD Setup Window
For more information on Loran TDs, you may download Garmin’s “Loran TD Position Format Handbook” from the Garmin web site.
103
Appendix C
Map Datums

The ‘User’ datum is based on a WGS-84 Local datum and is
an advanced feature for unlisted or custom datums. To learn
more, check your local library or on the world wide web for
educational materials on datums and coordinate systems.
104
Adindan
Adindan- Ethiopia, Mali, Senegal, Sudan
Chua Astro
Chua Astro- Paraguay
Afgooye
Afgooye- Somalia
Corrego Alegr
Corrego Alegre- Brazil
AIN EL ABD ‘70
AIN EL ANBD 1970- Bahrain Island,
Saudi Arabia
Djakarta
Djakarta (Batavia)- Sumatra Island
(Indonesia)
Anna 1 Ast ‘65
Anna 1 Astro ‘65- Cocos I.
Dos 1968
ARC 1950
ARC 1950- Botswana, Lesotho, Malawi,
Swaziland, Zaire, Zambia, Zimbabwe
Dos 1968- Gizo Island (New Georgia
Islands)
Dutch
Dutch
ARC 1960
Kenya, Tanzania
Easter Isld 67
Easter Island 1967
Ascnsn Isld ‘58
Ascension Island ‘58- Ascension Island
European 1950
Astro B4 Sorol Sorol
Atoll- Tern Island
Astro Bcn “E”
Astro Beacon “E”- Iwo Jima
Astro Dos 71/4
Astro Dos 71/4- St. Helena
European 1950- Austria, Belgium,
Denmark, Finland, France, Germany,
Gibraltar, Greece, Italy, Luxembourg,
Netherlands, Norway, Portugal, Spain,
Sweden, Switzerland
Astr Stn ‘52
Astronomic Stn ‘52- Marcus Island
European 1979
Aus Geod ‘66
Australian Geod ‘66- Australia, Tasmania
Island
European 1979- Austria, Finland,
Netherlands, Norway, Spain, Sweden,
Switzerland
Aus Geod ‘84
Australian Geod ‘84- Australia, Tasmania
Island
Finland Hayfrd
Finland Hayford- Finland
Gandajika Base
Gandajika Base- Republic of Maldives
Austria
Austria
GDA
Geocentric Datum of Australia
Bellevue (IGN)
Efate and Erromango Islands
Geod Datm ‘49
Geodetic Datum ‘49-New Zealand
Bermuda 1957
Bermuda 1957- Bermuda Islands
Guam 1963
Guam 1963- Guam Island
Bogata Observ
Bogata Obsrvatry- Colombia
Gux 1 Astro
Guadalcanal Island
Campo Inchspe
Campo Inchauspe- Argentina
Hjorsey 1955
Hjorsey 1955- Iceland
Canton Ast ‘66
Canton Astro 1966- Phoenix Islands
Hong Kong ‘63
Hong Kong
Cape
Cape- South Africa
Hu-Tzu-Shan
Taiwan
Cape Canavrl
Cape Canaveral- Florida, Bahama
Islands
Indian Bngldsh
Indian- Bangladesh, India, Nepal
Indian Thailand
Indian- Thailand, Vietnam
Carthage
Carthage- Tunisia
Indonesia 74
Indonesia 1974-Indonesia
CH-1903
CH 1903- Switzerland
Ireland 1965
Ireland 1965- Ireland
Chatham 1971
Chatham 1971- Chatham Island
(New Zealand)
ISTS 073 Astro
ISTS 073 ASTRO ‘69- Diego Garcia
Johnston Island
Johnston Island
Kandawala
Kandawala- Sri Lanka
NAD27 Mexico
N. American 1927- Mexico
Kerguelen Islnd
Kerguelen Island
NAD27 San Sal
Kertau 1948
West Malaysia, Singapore
North American 1927- San Salvador
Island
L. C. 5 Astro
Cayman Brac Island
NAD83
Liberia 1964
Liberia 1964- Liberia
North American 1983- Alaska, Canada,
Central America, CONUS, Mexico
Luzon Mindanao
Luzon- Mindanao Island
Nhrwn Masirah
Nahrwn- Masirah Island (Oman)
Luzon Philippine
Luzon- Philippines
(excluding Mindanao Isl.)
Nhrwn Saudi A
Nahrwn- Saudi Arabia
Nhrwn United A
Nahrwn- United Arab Emirates
Mahe 1971
Mahe 1971- Mahe Island
Naparima BWI
Marco Astro
Marco Astro- Salvage Isl.
Obsrvtorio ‘66
Massawa
Massawa- Eritrea (Ethiopia)
Merchich
Merchich- Morocco
Midway Ast ‘61
Midway Astro ‘61- Midway
Minna
Minna- Nigeria
Appendix C
Map Datums
Sao Braz
Sao Braz- Sao Miguel, Santa Maria
Islands
Naparima BWI- Trinidad and Tobago
Sapper Hill ‘43
Sapper Hill 1943- East Falkland Island
Observatorio 1966- Corvo and Flores
Islands (Azores)
Schwarzeck
Schwarzeck- Namibia
Sth Amrcn ‘69
S. American ‘69- Argentina, Bolivia,
Brazil, Chile, Colombia, Ecuador,
Guyana, Paraguay, Peru, Venezuela,
Trin/Tobago
Old Egyptian
Old Egyptian- Egypt
Old Hawaiian
Old Hawaiian- Mean Value
Oman
Oman- Oman
South Asia
South Asia- Singapore
Ord Srvy GB
Old Survey Grt Britn- England, Isle of
Man, Scotland, Shetland Isl., Wales
SE Base
Southeast Base- Porto Santo and Madiera
Islands
SW Base
Southwest Base- Faial, Graciosa, Pico,
Sao Jorge and Terceira Islands
NAD27 Alaska
North American 1927- Alaska
NAD27 Bahamas
North American 1927- Bahamas
(excluding San Salvador Island)
Pico De Las Nv
Canary Islands
North American 1927- Canada and
Newfoundland
Potsdam
Potsdam-Germany
Ptcairn Ast ‘67
Pitcairn Astro ‘67- Pitcairn
Taiwan
Modified Taiwan
Prov S Am ‘56
Chile,Colombia,
Prov So Amricn ‘56- Bolivia,
Ecuador, Guyana, Peru, Venezuela
Timbalai 1948
Timbalai 1948- Brunei and E. Malaysia
(Sarawak and Sabah)
Prov S Chln ‘63
So Chilean ‘63- S. Chile
Tokyo
Tokyo- Japan, Korea, Okinawa
Puerto Rico
Puerto Rico & Virgin Isl.
Tristan Ast ‘68
Tristan Astro 1968- Tristan da Cunha
Qatar
Qatar National- Qatar
User
User-defined custom datum
North American 1927-Central America
(Belize, Costa Rica, El Salvador,
Guatemala, Honduras, Nicaragua)
Qornoq
Qornoq- South Greenland
Viti Levu 1916
Viti Levu 1916- Viti Levu/Fiji Islands
Reunion
Reunion- Mascarene Island
Wake-Eniwetok
Wake-Eniwetok- Marshall
North Am. 1927- Mean Value (CONUS)
Rome 1940
Rome 1940- Sardinia Isl.
WGS 72
World Geodetic System 72
North American 1927- Cuba
RT 90
Sweden
WGS 84
World Geodetic System 84
Santo (Dos)
Santo (Dos)- Espirito Santo
Zanderij
Zanderij- Surinam
NAD27 Canada
NAD27 Canal Zone
North Am. 1927- Canal Zone
NAD27 Caribbn
North American 1927- Caribbean
(Barbados, Caicos Islands, Cuba, Dom.
Rep., Grd. Cayman, Jamaica, Leeward
and Turks Islands)
NAD27 Central
NAD27 CONUS
NAD27 Cuba
NAD27 Grnland
North American 1927- Greenland
(Hayes Peninsula)
105
Appendix D
Messages
The GPSMAP 178/178C uses an on-screen pop-up message system
to alert you to unit operating characteristics. Press the ENTER key to
acknowledge and return to the page you were viewing.
Alarm Clock— The alarm clock has sounded.
Alarm Voltage Set Too High— Voltage range must be between 10.0 and
35.0 volts for the GPSMAP 178/178C.
Alarm Voltage Set Too Low — Voltage range must be between 10.0 and
35.0 volts for the GPSMAP 178/178C.
Anchor Drag Alarm— You have drifted out of the specified distance
range.
Antenna Input Shorted To Ground— Check antenna wiring/connections
or antenna replacement.
Approaching Waypoint— You are a specified alarm distance from a
destination waypoint.
Arrival At Waypoint— You have arrived at the destination waypoint.
Basemap Failed Unit Needs Repair— Internal problem with the unit.
Contact your dealer or Garmin Product Support (pg. iv) to have the unit
serviced.
Battery Alarm— Specified amount of input voltage has been detected.
106
Battery Voltage High Please Check Connection— Input DC voltage is
too high for unit.
Battery Voltage Low Please Check Connection— Input DC voltage is
too low for unit.
Boat is Not Moving Fast Enough to Calibrate— Speed wheel is not
turning. Check for debris or boat speed is too slow.
Database Error— Internal problem with the unit. Contact your dealer or
Garmin Product Support (pg. iv) to have the unit serviced.
Deep Water Alarm— Specified deep water alarm depth has been detected
below transducer.
Lost Satellite Reception— The unit has lost satellite signals. Check
antenna connections or try moving to a location with a clear view of the sky.
Memory (RAM) Failed Unit Needs Repair— Internal problem with the
unit. Contact your dealer or Garmin Product Support (pg. iv) to have the
unit serviced.
Memory (ROM) Failed Unit Needs Repair— Internal problem with the
unit. Contact your dealer or Garmin Product Support (pg. iv) to have the
unit serviced.
No DGPS Position— No differential correction data is available or not
enough data is available to compute a DGPS position.
No Tide Stations For That Area— There are no tide stations within 100
miles of the specified point. Try another area.
Off Course Alarm— You have exceeded the specified off-course distance.
Processor Failed Unit Needs Repair— Internal problem with the unit.
Contact your dealer or Garmin Product Support (pg. iv) to have the unit
serviced.
Proximity Alarm List is Full— You have used all ten proximity
waypoints.
Proximity Alarm Waypoint— You have entered the alarm radius for the
proximity waypoint indicated.
Proximity Overlaps Another Proximity Waypoint—The alarm radius
specified overlaps the area specified for another proximity waypoint. Adjust
the distance.
Route Already Exists: <route name>— You have entered a route name
that already exists in memory. Modify the route name or delete the previous
route name.
Route Does Not Exist: <route name>— Route has been renamed or
removed from memory and cannot be used.
Route Is Full— You have attempted to add more than 50 points to a route.
Reduce the number of points or create a second route.
Route Memory Is Full Can’t Create Route— Maximum amount of 50
routes is already in the unit’s memory and no additional routes can be
added until existing ones are removed.
Route Truncated— An uploaded route from another device has more than
50 points. Reduce the number of points.
Running Simulator— The unit is in simulator (practice) mode.
Shallow Water Alarm— Specified shallow water alarm depth has been
detected below transducer.
Sonar Failed Unit Needs Repair— Internal problem with the unit.
Contact your dealer or Garmin Product Support (page. iv) to have the unit
serviced.
Track Already Exists: <track name>— You have entered a saved track
name that already exists in memory. Modify the track name or delete the
previous track name.
Appendix D
Messages
Track Memory Is Full Can’t Create Track— Track log memory is full.
No additional track log data can be stored without deleting old data to
create memory space.
Track Truncated— A complete uploaded track does not fit into memory.
The oldest track log points were deleted to make space for the most recent
data.
Transducer Disconnected Sonar Turned Off— No transducer attached
or bad cable/transducer.
Transfer Complete— The unit has finished uploading/downloading information to the connected device.
Water Speed Sensor is Not Working— Speed sensor is not detected.
Check connections.
Waypoint Already Exists: <waypoint name>— You have entered a
waypoint name that already exists in memory. Modify the waypoint name or
delete the previous waypoint name.
Waypoint Memory Is Full Can’t Create Waypoint— You have used all
3000 waypoints available. Delete unwanted waypoints to make space for
new entries.
107
Appendix E
Navigation Terms
108
Avg Speed— The average of all second-by-second speed readings since last reset.
Bearing (BRG)— The compass direction from your present position to a destination waypoint.
Course— The desired course between the active ‘from’ and ‘to’ waypoints.
Distance (Dist)— The ‘great circle’ distance from present position to a destination waypoint.
Distance to Destination— The ‘great circle’ distance from present position to a Go To destination, or
the final waypoint in a route.
Distance to Next— The ‘great circle’ distance from present position to a Go To destination, or the
next waypoint in a route.
Elevation— Height above mean sea level (MSL).
ETA— Estimate Time of Arrival. The estimated time you will reach your destination waypoint, based
on current speed and track.
ETA at Destination— The estimated time you will reach a Go To destination, or the final waypoint in
a route.
ETA at Next— The estimated time you will reach a Go To destination, or the next waypoint in a route.
Fuel— The fuel required to travel from present position to the indicated route waypoint.
Leg Dist— The distance between two route waypoints.
Leg Fuel— The fuel required to travel from a route waypoint to the next waypoint (in sequence) in the
route.
Leg Time— The time required to travel from a route waypoint to the next waypoint (in sequence) in
the route.
Max Speed— The maximum second-by-second speed recorded since last reset.
Moving Average Speed— Average speed while the unit is moving.
Moving Trip Timer— Total time the unit has been moving.
Appendix E
Navigation Terms
DIS
NORTH
NORTH
TAN
CE
TO
DES
TINA
TIO
N
DESTINATION
WAYPOINT
BRG
TRK
SP
EE
D
SE
UR
CO
DES
IR
TRA ED
CK
F
OF
Odometer— A running tally of distance travelled, based upon the distance between second-by-second
position readings.
Off Course— The distance you are off a desired course in either direction, left or right. Also referred
to as ‘cross-track error’ or ‘course error’.
Speed— The current velocity at which you are travelling, relative to a ground position. Also referred to
as ‘ground speed’.
Time To— The estimated time required to reach a Go To destination, or the next waypoint in a route.
Also referred to as ‘estimated time en route’.
Time to Destination— The estimated time required to reach a Go To destination, or the final
waypoint in a route.
Time to Next— The estimated time required to reach a Go To destination, or the next waypoint in a
route.
To Course— The recommended direction to steer in order to reduce course error or stay on course.
Provides the most efficient heading to get back to the desired course and proceed along your route.
Track— The direction of movement relative to a ground position. Also referred to as ‘ground track’.
Trip Odometer— A running tally of distance travelled since last reset. Also see ‘Odometer’.
Total Average Speed— Average speed of unit for both moving and stopped speeds since last timer
reset.
Total Trip Timer— Total time the unit has been in operation since last reset of the trip timers.
Turn— The angle difference between the bearing to your destination and your current track. ‘L’ indicates you should turn left, ‘R’ indicates you should turn right. The degrees indicate the angle you are off
course.
VMG— Velocity Made Good. The speed you are closing in on a destination along a desired course.
Also referred to as the ‘vector velocity’ to your destination.
'FROM'
WAYPOINT
109
The chart below gives an approximate UTC (Universal Time Coordinate) time offset for the various
longitudinal zones. Check with local charts for more detailed information. If you are in daylight
savings time, add one hour to the offset.
Appendix F
Time Offsets
Longitudinal Zone
Offset
W180.0º to W172.5º
-12
W172.5º to W157.5º
-11
W157.5º to W142.5º
-10

W142.5º to W127.5º
-9
W127.5º to W112.5º
-8
A simple way to determine your local time offset is how
many hours you are behind or ahead of UTC (also called
‘Greenwich’ or ‘zulu’ time).
Example: EST (Eastern Standard Time) is 5 hours behind
UTC, so your offset would be -5. Adding one hour for daylight savings would make EDT (Eastern Daylight Time)
- 4. Subtract an hour for each time zone as you travel west.
W112.5º to W097.5º
-7
W097.5º to W082.5º
-6
W082.5º to W067.5º
-5
W067.5º to W052.5º
-4
W052.5º to W037.5º
-3
Offsets for Continental U.S. would be:
EST
-5
CST
-6
MST
-7
PST
-8
W037.5º to W022.5º
-2
W022.5º to W007.5º
-1
110
EDT
CDT
MDT
PDT
-4
-5
-6
-7
W007.5º to E007.5º 0
Longitudinal Zone
Offset
E007.5º to E022.5º
+1
E022.5º to E037.5º
+2
E037.5º to E052.5º
+3
E052.5º to E067.5º
+4
E067.5º to E082.5º
+5
E082.5º to E097.5º
+6
E097.5º to E112.5º
+7
E112.5º to E127.5º
+8
E127.5º to E142.5º
+9
E142.5º to E157.5º
+10
E157.5º to E172.5º
+11
E172.5º to E180.0º
+12
Understanding Sonar
If you are unfamiliar with basic sonar, or need help determining what is displayed on the graph, this
section may be for you. This section is intended to help the novice user gain some understanding of how
the GPSMAP 178/178C operates and how it can help improve their fishing productivity.
To understand what the unit is displaying, it is important to have a general knowledge of how the
unit works and how it determines what to display. Briefly described, the unit operates by transmitting
sound waves toward the bottom of a lake, stream, or seabed in a cone shaped pattern. When a transmitted soundwave strikes an underwater object such as the bottom, a piece of structure, or a fish, sound is
reflected back to the transducer. The transducer collects the reflected sound waves and sends the data to
the unit to be processed and displayed on the chart. The underwater data is displayed on the chart in the
order that it is returned: first returned—first on the chart. The diagram in the sidebar demonstrates this
showing an underwater scene as it would be displayed on the chart. Generally speaking, if the only thing
between the transducer and the bottom is water, the first strong return comes from the bottom directly
below the transducer. The first strong return sets the bottom level. Weaker secondary returns provide the
detailed data. Stronger returns displays in darker colors, black being the strongest return. In Example 3
(page 113) you can see that the branches and the fish where the strongest secondary returns are indicated
in black on the display.
That is brief description of how your GPSMAP 178/178C operates. Let’s take a look at how this data
can help you to improve your fishing.
Appendix G
Understanding Sonar
This fish is currently in a dead zone and is not detected by
the sonar. The fish is in the coverage area of the transducer,
but remember– the first strong return sets the bottom level.
The fish is eventually detected when the first strong return
sets the bottom level below the fish.
111
Appendix G
Transducer Coverage
Transducer Coverage
The area covered by the transmitted sound waves is determined by the cone angle of the transducer
and the water depth. Cone angles may vary between different types of transducers. For example, a 50kHz
frequency may provide a “wide” 40° cone angle, with a coverage width that is approximately 2/3 of the
water depth. As shown in the sidebar, the 40° cone angle (50kHz frequency) approximately covers the
area of a 20 foot diameter circle at a 30 foot depth. A 200kHz frequency may provide a “narrow” 10°
cone angle, with a coverage width that is approximately 2/10 of the water depth. As shown, the 10° cone
angle (200kHz frequency) approximately covers the area of a 6 foot diameter circle at a 30 foot depth.
When using the GPSMAP 178/178C in ‘Dual’ frequency mode, the unit transmits both 50kHz and
200kHz signals at the same time. The ‘Dual’ frequency capability of the GPSMAP 178/178C allows you
to have a large coverage area and still retain good bottom resolution. When in ‘Dual’ frequency mode the
unit uses the narrow cone angle (200kHz) to display detailed bottom information, keeping “Dead Zones”
to a minimum, and the wide cone angle (50kHz) for the large coverage area.
Fish returns from the wide and narrow beams appears differently on the display. The wide beam
tends to show longer fish returns than the narrow beam.
200kHz - 10˚ Cone Angle
72" coverage at 30'
50kHz - 40˚ Cone Angle
20' coverage at 30'
Wide Cone Angle
112
Narrow Cone Angle
Understanding the Graph
It is important to understand that the unit does not display a 3-D representation of the underwater
environment. The unit can display multiple things at the same time, but cannot determine where the
return originated – only when it was received.
Examples 1 and 2 provide a look at the underwater world from a top view, and illustrate how these
views would be displayed on the graph. On both graphs it appears the fish and tree are side by side as
shown in Example 1. However, when we look at Example 2, we see that the fish can be several feet from
the tree. It is important to remember that the sonar cannot determine where in the coverage area the tree
or fish are, only that the returns were received at the indicated depths in the same time frame.
Appendix G
Understanding the Chart
Enlarged
Transducer
View
Enlarged
Transducer
View
Example 1.
Branches
Branches
Fish
Fish
Example 2.

Remember that the sonar displays a 2-D picture of the
underwater environment. The fish and tree could be
located anywhere in the coverage area at that time.
113
Whiteline
Appendix G
Understanding the Graph

Whiteline can also help you to determine the type of bottom
structure that is displayed on the chart. By determining the
hardness of the structure, you can make a better informed
decision on the type of structure.
Structure is hard—
probably a rock or stump
Structure is soft—
probably a mud pile
The GPSMAP 178/178C can help you to determine if the bottom is hard or soft. When the sonar
soundwaves are reflected back by the bottom, a hard bottom returns a stronger signal than a soft bottom.
A thin whiteline indicates a softer bottom while a thick whiteline indicates a harder bottom. Normally,
a red/dark line is used to show the point where water meets the bottom. This line follows the bottom
contour, along with any significant objects lying on the bottom. The unit uses the whiteline function to
make this bottom layer information easier to distinguish.
With the GPSMAP 178/178C, active whiteline helps accentuate where strong signals are located,
which make bottom type determination easier. The example to the right shows the bottom return with
and without the whiteline activated.
Hard Bottom
Whiteline
Soft Bottom
Example 4.
114
Whiteline Turned Off
Thermoclines
One of the unique features offered by Garmin is See-Thru technology. See-Thru technology allows
the GPSMAP 178/178C to “see” through thermoclines and helps locate fish where they live; and fish
love thermoclines! A rough definition of a thermocline is a break in water where the water temperature
changes faster than the water above it. Thermoclines are shown as the weakest colors (see pg. 14).
Appendix G
Understanding the Graph
Thermocline
115
Appendix H
Specifications
Physical Specifications
Size:
Weight:
Display:
4.9" H x 6.3" W x 3.7" D (122.5mm x 157.5mm x 92.5mm)
1.0 lb 3.5oz.(.553Kg)
(178C) 3.2” W x 3.2” H (81.28mm) CSTN (Color Super Twist Nematic) with
adjustable CCFL (Cold Cathode Fluorescent Lamp) backlighting; (320x320
pixels)
(178) . 3.2” W x 3.2” H (81.6 mm) 10 level grayscale FSTN (Film Super Twist
Nematic) with adjustable CCFL (cold cathode) backlighting; (320x320 pixels)
Case: Fully gasketed, high-impact plastic alloy, waterproof to IEC 60529-IPX-7
Temp. Range: 5°F to 158°F (-15°C to 55°C)
Performance
Receiver:
Differential-ready 12 parallel channel WAAS capable receiver
Acquisition Times:
Warm:
Approx. 15 seconds
Cold:
Approx. 45 seconds
AutoLocate: Approx. 2 minutes
Update Rate:
1/second, continuous
GPS Accuracy: Position*: <15 meters (49 feet), 95% typical*
Velocity: 0.05 meters/sec steady state
DGPS (USCG) Accuracy:
Position: 3-5 meters (10-16 feet) with optional Garmin DGPS receiver, 95% typical*
Velocity: 0.05 meters/sec steady state
DGPS (WAAS) Accuracy:
Position: <3 meters (10 feet), 95% typical*
Velocity: 0.05 meters/sec steady state
Dynamics:
6g's
116
* Subject to accuracy degradation to 100m 2DRMS under the U.S. DOD-imposed Selective Availability Program.
Power
Source:
Usage:
Fuse:
10-35 vDC
8 watts max. at 13.8 vDC
AGC/3AG - 2.0 Amp
Sonar
Sounder Power: 500 watts (RMS), 4000 watts (peak to peak) with dual frequency transducer
400 watts (RMS), 3200 watts (peak to peak) with single frequency transducer
Frequency:
Depth:
50/200 kHz dual frequency; 200 kHz single frequency
1500 foot max depth (dual frequency)*
900 foot max depth (single frequency)*
* Depth capacity is dependent on water salinity, bottom type and other water conditions.
Appendix H
Specifications/
Unit Care
UNIT CARE
Cleaning - The unit’s case is constructed of high quality
material and does not require user maintenance other
than cleaning. Clean the unit housing using a cloth lightly
dampened with a mild detergent solution and then wipe
dry. Avoid chemical cleaners and solvents that may damage
plastic components. Do not apply cleaner to electrical
contacts on the back of the unit.
Storage - Do not store the unit where exposure to temperature extremes may occur (see left), as permanent damage
may result. User information, such as waypoints, routes,
etc. is retained in the unit’s memory, without the need for
external power. It is always a good practice to back up
important user data by manually recording it or downloading it to a PC (see pg. 86).
Water Immersion -The GPSMAP 178/178C is
waterproof to IEC Standard 60529 IPX7. It can withstand
immersion in 1 meter of water for 30 minutes. Prolonged
submersion can cause damage to the unit. After submersion,
be certain to remove the data card and dry the compartments before reuse.
To resolve problems that cannot be remedied using this
guide, contact Garmin Product Support in the U.S.A. at
800-800-1020 or Garmin Europe at 44-1794-519944.
117
Appendix I
Index
A
Accuracy 69
Accuracy Alarm 90
Accuracy Circle 29
Active Route Page 19, 43, 64
Adjustments, Sonar 36
Adjustment Menu 15, 33, 34, 36
Alarm Tab 90, 91
Anchor Drag Alarm 90
Append to Route 47
Arrival Alarm 90
ARROW KEYPAD 1
AutoLocate 71
AutoZoom 27
B
Background Color 39
Backlight 6
BACKLIGHT Key 1
Basemap 27
Battery Alarm 90
Bearing Line 29
118
Bearing Pointer 41
Beeper 83
BlueChart 27, 28
Bottom Lock 34
Bottom Split 34
C
Calibrate Water Speed 39, 40
Capabilities v
Card Tab 82
Cautions iii
Celes Tab 74
Change Numbers 18, 30, 40, 43
Cleaning 117
Clock Alarm 90
Color, Sonar Background 39
Color Bar 39
Color Mode 27
Communications Tab 86-90
Compass Page 16, 41
Compass Page options 41
Compass Ring 16, 41
Contrast 1, 6
Copying Routes 59
Course Line 29
Course Up 27
Creating Map Waypoints 13
Creating Routes 57, 58
Creating Waypoints 44-47, 50
Cursor 9, 13, 22-24
Product Support i
D
Data Cards 101
Data Card Maps 27
Data Fields 18, 30
Data Transfer 86, 87
Datum 85
Daylight Savings 86, 110
Declutter 31
Deep Water Alarm 91
Defaults 29, 40, 84
Deleting Routes 59
Deleting Tracks 76
Deleting Waypoints 49, 51
Depth Line 15, 36
Depth Number 38
Depth Units 85
Detail 27
DGPS 87, 88, 96
DGPS Alarm 90
Distance Units 85
DSC (Digital Selective Calling) 77
DSC Call List 80
DSC Directory 80, 81
DSC Distress Call 78, 79
DSC Entry Review 80
DSC Log 80
DSC Position Report 78, 79
DSC Setup 81
DSC Simulation 82
DSC Tab 77-81
DSC Tabs 82
Dual Frequency 14
E
Editing Routes 60-63
Editing Waypoints 48, 49
Elevation Units 85
Entering Data 3
ENTER Key 1
Erasing Tracks 75
F
FCC Compliance ii
Find 65, 66
FIND Key 1, 65
Find Options 66
Fish Alarm 91
Fish Symbols 38
Flasher 39
Following Routes 58, 59
Follow Route 11
Follow Track 11, 54
Frequency 14, 15, 35
Full Screen Map 25
G
Gain 15, 35
General Tab 27
Going to a Destination 11, 53, 54
Go To 53
Go To Point 11, 53
GPS Information Page 5, 6
GPS Status 5, 70
GPS Tab 68-71
Grids 84
Appendix I
H
Heading 85
Heading Line 29
Hide Numbers 37
Hide Pointer 37
Highway Page 17, 18, 42
Highway Page options 42
Highway Scale 42
How To Index viii
I
Initialize Position 71
Initializing 4
Installation 92-100
Interfacing 96
IN Key 1, 22, 24
K
Keel Offset 39, 40
Keypad 1, 2
L
Language 83
Lat/Lon Grid 29
Light Sectors 28
Loran TD 84, 102, 103
Loran TD Setup 103
Index
M
Magnetic North 85
Main Menu 20
Main Menu Page 67
Main Menu Tabs 67, 68
Main Pages 8
Map, Set Up 26
Map/Sonar Split Page 14, 32
MapSource 27
Map Cursor 9
Map Datums 85, 104, 105
Map Information Page 27
Map Item 11
Map Outlines 29
Map Page 8, 9, 22
Map Page Options 25
Map Scales 12, 24
Map Split Sonar Detail 39
Marking Position 44
Marking Waypoints 10
MARK Key 1, 44, 45
Measure Distance 26
119
Appendix I
Index
MENU Key 1
MENU key 20
Merge From Card 82
Messages 106, 107
MGRS 84
MMSI Number 77, 78, 81
MOB 56
MOB Key 1, 56
Moon Phase 74
Moon Rise/Set 74
Mounting the Transducer 98, 99
Move Waypoint 47
Moving Waypoints 49
N
Navaids, Set Up 28
Navaids Tab 28
Navigation Terms 108, 109
NAV Key 1, 53-56, 82
Nav Line Tab 29
Nearest To Boat 66
Nearest To Destination 66
120
Nearest To Next 66
Nearest To Other 66
New Waypoint 46
NMEA 86-90, 96
NMEA Interface 89
NMEA Output Setup 89
Noise Reject 15, 36
North Reference 85
North Up 27
Numbers 30, 40
O
Off Course Alarm 90
Orientation 27
Other Tab 29
OUT Key 1, 22, 24
Overzoom 24
P
Packing List vi
PAGE Key 1
Page Layout 19, 29, 40, 43
Pointer 37
Points Tab 28
Position Format 84
Power 4, 6
POWER Key 1, 21
Projecting Waypoints 46
Proximity Alarms 52
Proximity Waypoints 51, 52
Q
QUIT Key 1
R
Range 15, 34
Receiver Status 69, 70
Registration i
Replace From Card 82
Reset All 74
Reset Max Speed 74
Reset Odometer 74
Reset Trip 74
Retail Demonstration 7
Reviewing Routes 60
Reviewing Tracks 76
Reviewing Waypoints 48
Routes 57
Routes, Copying 59
Routes, Creating 57, 58
Routes, Deleting 59
Routes, Editing 60-63
Routes, Following 58, 59
Routes, Reviewing 58, 60
Routes, TracBack 54
Routes, Trip Planning 63
Route List Page 59
Route Review Options 60
Route Review Page 60
S
Saved Tracks 76
Savings Tracks 75
Scale, Highway 42
Scale, Map 24, 39
Scroll, Sonar 15, 36
Selecting Options 2
Serial Number iv
Serial Number, Electronic 84
Service iv
Setup Tab 83
Set 2D Elevation 71
Set Up Highway 43
Set Up Map 26
Set Up Page Layout 19, 29, 40, 43
Set Up Sonar 38
Shallow Water Alarm 91
Show Data 25
Show Numbers 37
Show Pointer 37
Signal Strength Bars 68
Simulated Tour 12
Simulator 71, 83
Simulator Mode 7, 11, 17
Simulator Set Position 83
Simulator Speed 84
Simulator Track Control 84
Simulator Transducer 84
Size Split 32, 37, 38
Skyview Orientation 74
Software License Agreement i
Software Version 84
Sonar, Set Up 38
Sonar, Understanding 111-115
Sonar Page 14, 15, 33
Sonar Page Options 36
Sonar Tab 38
Sonar Tab Options 38
Source Tab 27
Span 15, 35
Specifications 116, 117
Speed Filter 83
Speed Units 85
Split 34
Stop Navigation 11
Storage 117
Sun Rise/Set 74
Symbol Set 28
System Information 84
System Mode 83
System Tab 84
T
Table of Contents vii
Target Level 15, 35
Temperature Graph 39
Temperature Scale 83
Temperature Tab 83
Temperature Time Duration 83
Temperature Units 85
Thermoclines 115
Tides 72, 73
Tide Tab 73
Appendix I
Index
Time Format 86
Time Offsets 110
Time Zone 86
TracBack 54-56, 76
Tracks, Deleting 76
Tracks, Erasing 75
Tracks, Reviewing 76
Tracks, Saved 76
Tracks, Saving 75
Track Color 75
Track Interval 75
Track Logs 54, 55, 75
Track Record Mode 75
Track Tab 29, 54, 55, 75, 76
Track Up Below 27
Track Value 75
Transducers 97, vi
Transducers, Mounting 98, 99
Transducer Coverage 112
Transfer Mode 87
Trip Data 74
Trip Planning 63
121
Appendix I
Index
Trip Tab 74
Turn Declutter On/Off 31
U
Understanding Sonar 111-115
Understanding the Graph 113-115
Underwater Waypoints 37
Units 84, 85
Unit Care 117
User Datum 104
User Waypoint List 50
V
View 15, 35
W
WAAS 69, 71
Warnings iii
WARRANTY iv
Water Immersion 117
Water Speed 39, 40
Water Temperature Alarm 91
122
Water Type 38
Waypoints, Append to Route 47
Waypoints, Creating 10, 13, 24, 44-47,
50
Waypoints, Creating Underwater 37
Waypoints, Deleting 20, 49, 51
Waypoints, Editing 48, 49
Waypoints, Moving 47, 49
Waypoints, Projecting 46
Waypoints, Proximity 51
Waypoints, Reviewing 13, 48
Waypoints Tab 28
Waypoint List 50
Waypoint Menu Options 47
Waypoint Symbols 10, 48
Whiteline 15, 35, 114
Wiring 96
Z
Zoom, Map 24
Zoom, Sonar 14, 15, 34
For the latest free software updates (excluding map data) throughout the life of your
Garmin products, visit the Garmin Web site at www.garmin.com.
© Copyright 2004 Garmin Ltd. or its subsidiaries
Garmin International, Inc.
1200 East 151st Street, Olathe, Kansas 66062, U.S.A.
Garmin (Europe) Ltd.
Unit 5, The Quadrangle, Abbey Park Industrial Estate, Romsey, SO51 9DL, U.K.
Garmin Corporation
No. 68, Jangshu 2nd Road, Shijr, Taipei County, Taiwan
www.garmin.com
Part Number 190-00321-02 Rev. B