PADI Open Water Diver Course - Chapter Five

PADI Open Water Diver Course - Chapter Five
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FIVE
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Special Dive Table and
Computer Procedures
In Section Four you learned the basics for
diving with dive tables and dive computers,
but there are some additional procedures
that you need to know about. These involve
procedures for enhanced safety, for accidentally exceeding your no-stop limit, and for
diving at altitude or ascending to altitude
after diving.
Safety Stops
Although as a recreational diver you plan
only no decompression dives that allow you to
ascend directly and continuously to the surface, most of the time you’ll want to make a
safety stop for added conservatism. A safety
stop provides extra time for your body to
eliminate nitrogen, and it gives you a
moment to stabilize and control your ascent
rate before continuing to the surface.
To make a safety stop, you stop your ascent
in the 3 to 6 metre/10 to 20 foot range — usually at 5 metres/15 feet for three minutes or
longer. It’s easiest to do this holding onto a
line or on an ascending slope, but you can
also hover in midwater where appropriate.
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Underline/highlight the answers
to these questions as you read:
1. What are the recommended
depth and time for a safety
stop?
2. What’s the purpose of a
safety stop?
3. What are three situations in
which a safety stop is considered required?
Special Dive Table
and Computer
Procedures
Using a Dive
Computer
Basic Compass
Navigation
Continuing Your
Adventure
Using the
Recreational Dive
Planner (Continued)
Confined Water Dive
Preview
Open Water Dives
3, 4 and Optional
Skin Dive
Dive Safety Practices
Summary
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You plan your dive so you can make a safety stop and
still reach the surface with 20-40 bar/300-500 psi or
more air remaining in your cylinder.
You may make a safety stop at the end of any dive,
and in fact, you should consider it a standard practice
on virtually all your dives. However, consider a safety
stop required if:
1. Your dive has been to 30 metres/100 feet or deeper.
2. Your pressure group at the end of the dive is within
three pressure groups of the no decompression limit
on the RDP.
3. You reach any limit on the Recreational Dive
Planner or your dive computer. With a dive computer, this would be if your computer shows zero
NDL time remaining at any point in the dive.
When using the RDP, in these circumstances the
safety stop is considered required.
You may wonder whether you need to account
for safety stop time when using the RDP. You
don’t need to add safety stop to your bottom
time when using the Recreational Dive Planner. A
computer will process safety stop time automatically.
Keep in mind that, although you should make safety
stops a regular procedure for all your dives, it’s
optional under circumstances such as very low air
(due to unforeseen circumstances during the dive),
assisting another diver, or rising bad weather make it
more important to get to the surface immediately.
Q
Q
UICK
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2. The purpose of a safety stop is
(check all that apply):
a. to drain your tank as much as
possible.
b. to allow your regulator to stabilize its performance.
c. to give your body extra time to
eliminate nitrogen.
d. to allow you to stabilize and control your ascent.
3. A safety stop is considered
required when (check all that
apply):
a. you dive to 30 metres/100 feet or
deeper.
b. you reach any limit on your table
or computer.
c. your dive comes within three
pressure groups of an NDL on the
RDP.
d. you’re almost out of air.
How’d you do?
1. b. 2. c, d. 3. a, b, c.
You plan your dive as a no decompression dive but
something delays your ascent and you accidentally exceed the no
stop limit. Now what? You need to make an emergency decompression stop to allow your body to eliminate nitrogen; without this
stop, you face an unacceptable risk of DCS when you surface.
Using the RDP: If you exceed a no decompression limit or
(on a repetitive dive) an adjusted no decompression limit by
Open Water Diver Manual
Self Assessment 1
1. The recommended general depth
and time for a safety stop is:
a. 10 metres/35 feet for 2 minutes.
b. 5 metres/15 feet for 3 minutes.
c. 2 metres/6 feet for 20 minutes.
Emergency Decompression
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five minutes or less, slowly ascend at a
rate not faster than 18 metres/60 feet
per minute to 5 metres/15 feet and
remain there for eight minutes prior to
surfacing. After reaching the surface, do
not dive for at least six hours because
you will have extremely high levels of
residual nitrogen in your body.
If you exceed a no decompression
limit or an adjusted no decompression limit by more than five
minutes, a 5 metre/15 foot stop for no
less than 15 minutes is strongly urged,
air supply permitting. Upon surfacing,
you must remain out of the water at
least 24 hours before diving again, due to the excess nitrogen
in your body.
When making an emergency decompression stop, stay as close
to 5 metres/15 feet as possible. If you don’t have enough air for
the emergency decompression stop, stay as long as you can,
saving enough air to surface and exit safely. Discontinue diving for no less than 24 hours. Breathe pure oxygen if available
and monitor yourself for decompression sickness symptoms.
Using a dive computer: If you exceed your computer’s no
decompression limits, it will go into decompression mode,
which guides you through the emergency decompression stop.
Computers differ in how they function in decompression mode,
so consult the manufacturer’s literature for the specifics for
your computer. Many will show emergency decompression
stops at 3 metres/10 feet instead of 5 metres/15 feet; stopping
at 5 metres/15 feet until the computer says you can surface
will still work, though, because the computer calculates the
stop based on your actual depth. It may take a bit longer than
the time indicated for a stop at 3 metres/10 feet.
It’s not recommended that you make a repetitive dive after a
dive requiring emergency decompression. Emergency decompression stops differ from safety stops in that an emergency
decompression stop must be made or there is an excessive risk
of decompression sickness, and that is an emergency procedure
Wait a few minutes.
You’ll want to make a safety stop for
added conservatism as you finish
most of your dives. The stop provides
extra time to eliminate nitrogen, and
it gives you a moment to stabilize
your ascent rate.
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Underline/highlight the answers to
these questions as you read:
4. What should you do if you
exceed a no decompression
limit or an adjusted no decompression limit by five minutes
or less when using the RDP?
5. What should you do if you
exceed a no decompression
limit or an adjusted no decompression limit by more than five
minutes when using the RDP?
6. How do you determine emergency decompression requirements with a dive computer?
Chapter Five
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only in recreational diving. The Recreational Dive
Planner was designed for recreational, no decompression diving only. It should never be used in
commercial/military/technical diving situations
that require planning for decompression dives.
Altitude Diving, Flying After Diving, and
Cold/Strenuous Dives
Going under when you’re upper.
If you’re interested in high-altitude diving, see your
PADI Dive Center, Resort or Instructor about learning
the techniques in an Advanced Open Water adventure
dive, or by taking an Altitude Diver specialty course.
For more i
n about...
nformatio
Altitude Diving
See the PADI Adventures
in Diving Manual
Q
Q
Altitude Diving. Thinking back to Section One, you
recall that as you ascend in air, pressure
decreases. Dive tables and most computers give
you their no decompression limits based on a dive
ending at sea level; if you’re under less pressure at
altitude, nitrogen comes out of solution more easily
following a given dive, making decompression sickness more likely.
You can use the Recreational Dive Planner for diving to altitudes as high as 300 metres/1000 feet.
Above 300 metres/1000 feet, you need special conversion tables and procedures to account for the
UICK
UIZ
1. If you exceed your no decompression limit or adjusted no
decompression limit by less
than five minutes when using
the RDP, you should
a. slowly ascend to 5
metres/15 feet and make an
eight minute stop, then not
dive for at least six hours.
b. slowly ascend to 5
metres/15 feet and make a
three minute stop, then not
dive for at least six hours.
c. None of the above.
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HELP
Self Assessment 2
2. If you exceed your no decompression limit or adjusted no
decompression limit by more
than five minutes when using
the RDP, you should
a. slowly ascend to 5
metres/15 feet and make a
stop for at least 15 minutes,
air supply permitting, then not
dive for at least 24 hours.
b. slowly ascend to 5
metres/15 feet and make an
eight minute stop, then not
dive for at least six hours.
c. None of the above.
3. If you exceed the no decompression limit of your dive
computer, make an emergency decompression stop
as it directs in its decompression mode, and do not make
a repetitive dive.
True
False
How’d you do?
1. a. 2. a. 3. True
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MAIN
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Underline/highlight the answers to
these questions as you read:
7. Above what altitude do you
need to use special dive procedures?
8. What are the recommendations
for flying in a commercial airliner after diving?
9. What are the procedures for
planning a dive in cold water or
under strenuous conditions?
decreased atmospheric pressure or you can run an
unacceptable risk of DCI.
The procedures for diving at altitude with a dive
computer vary with the computer. Some automatically compensate for altitude, whereas with others
you’ll need to tell the computer your altitude. There
are a few older models that you can’t use at altitude.
If you’re interested in high-altitude diving, see
your PADI Dive Center, Resort or Instructor about
learning the techniques in an Advanced Open
Water adventure dive, or by taking an Altitude Diver
specialty course (usually takes less than a day).
Flying After Diving. You also need to think about
lowered atmospheric pressure if you plan to fly
after diving. While this concern is similar to altitude diving, it’s not identical. When you dive at
altitude, you dive and return to reduced atmospheric pressure. When you fly after diving, you dive
and return to normal atmospheric pressure, then
expose yourself to further pressure reduction.
The dive medical community offers the following general recommendations for flying
after diving, whether you’re using the RDP,
another table or a dive computer:
Wing your way carefully.
You’re responsible for your own dive safety. Flying after
diving recommendations change over time; stay up to
date and follow the most current recommendations.
For Dives within the No-Decompression Limits
• Single Dives – A minimum preflight surface
interval of 12 hours is suggested.
• Repetitive Dives and/or Multiday Dives –
A minimum preflight surface interval of 18
hours is suggested.
Flying After Diving
Flying after diving recommendations change over
time. These are current at
the time of printing. Always
check with your instructor
to stay apprised of the
most current ones.
For Dives Requiring Decompression Stops
• A minimum preflight surface interval greater
than 18 hours is suggested.
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As with dive tables and computers, no flying after diving
recommendation can guarantee that decompression sickness will never occur. These guidelines represent the best
estimate presently known for a conservative, safe surface
interval for the vast majority of divers. There always may
be an occasional diver whose physiological makeup or special dive circumstances result in decompression sickness
despite following the recommendations.
You’re responsible for your own dive safety and
behavior. Flying after diving recommendations
change as we learn more about how pressure
changes affect the body; stay current and follow
the most current recommendations.
There are currently no recommendations for driving to altitude after diving, so the most prudent
practice is to be conservative. The longer you wait
before you go, the lower your risk. You may check
with a local dive center, resort or instructor to see
if divers in the area follow a particular recommendation or protocol.
Cold and Strenuous Conditions. If you get cold or
exercise a lot during a dive, you may end your
dive with more excess nitrogen in your body than
calculated by your dive table or computer. When
using the RDP for planning a dive in cold water or
under conditions that may be more strenuous
than usual, plan your dive as though the depth
were 4 metres/10 feet deeper than it actually is.
Q
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Open Water Diver Manual
Self Assessment 3
1. When using the RDP, you need to
use special dive procedures above
what altitude? ____________
2. The minimum recommended surface interval for flying after diving is
_________.
3. Using the RDP, under cold and
strenuous conditions you plan your
dive as though:
a. it were at altitude.
b. it were 4 m/10 ft deeper than
actual.
c. it were 4 m/10 ft shallower than
actual.
d. None of the above.
How’d you do?
1. 300 m/1000 ft. 2. 12 hours. 3. b.
How you handle this with a dive computer
depends on the computer. A few sophisticated
models track the water temperature and your
breathing rate and automatically readjust to more conservative no stop times when necessary. For others, you can set
the computer to be more conservative by using the altitude
setting and setting it to an altitude higher than you actually are, or by connecting the dive computer to a personal
computer (requires special hardware and software).
However, you have to make these settings before the dive.
If you can’t set your computer to be more conservative (and
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it doesn’t do it automatically), or if you didn’t expect cold/strenuous conditions, you’ll need to be more conservative by making
sure you always have plenty of no decompression time remaining
throughout the dive.
It’s especially prudent to make a safety stop when diving in cold
water or under strenuous conditions.
Using a Dive Computer
As you learned in Section Four, you’re probably going to be diving
with a computer more often than not. The basic principles and
guidelines that apply to the RDP apply, for the most part, to diving with your computer. Keep these points and procedures in
mind:
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Underline/highlight the answers
to these questions as you read:
10. What procedures and
general recommendations
apply to diving with a
computer?
1. Computers are sophisticated calculators with depth
gauges and timers that calculate theoretical nitrogen in
the body. They’re no more or less valid than dive tables, and
they don’t track anything physical in your body. The recommendations for conservative diving with tables apply to computer
diving.
2. Don’t share your computer. Each diver needs an individual
computer. A computer tracks theoretical body nitrogen as it rises
Summary Points
In this subsection on Special Dive Table and
Computer Procedures, you learned:
▲ For recreational divers, decompression is
only an emergency procedure.
▲ You should make a safety stop at the end of
virtually all dives (except when an emergency
prohibits it).
▲ You need to follow special procedures when
diving at an altitude greater than 300
metres/1000 feet.
▲ A safety stop is a pause in your ascent
between 3 and 6 metres/10 and 20 feet for
three minutes or longer.
▲ Follow the recommendations for flying after
diving conservatively, and stay up to date
with the most current recommendations.
▲ Consider a safety stop mandatory if you dive
deeper than 30 metres/100 feet or reach any
limit on the RDP or your computer.
▲ Plan cold/strenuous dives with the RDP as
though the depth were 4 metres/10 feet
deeper than actual. With a computer, be conservative using the most appropriate method
for your computer.
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and falls with each dive and surface interval, so it
must stay with one diver for the entire dive day — you
can’t swap between dives. You can’t share a computer
within a buddy team either because it tracks depth
quite closely. It will only be accurate for the diver wearing the computer.
3. Follow the most conservative computer. Surface
or ascend when either computer — yours or your
buddy’s — approaches its no decompression limit. If
you follow the least conservative, you’re in effect sharing that computer, which you shouldn’t do.
4. Don’t turn your computer off between dives.
Most won’t let you, but if you take out the battery or
shut the computer down, it loses its memory of your
previous dives and your residual nitrogen. You’ll have
to allow all residual nitrogen to leave your body before
resuming use of the computer. Your computer will shut
itself off when it calculates no significant residual
nitrogen remaining.
5. Make your deepest dive first and plan successive dives to progressively shallower depths.
During a dive, start at the deepest point and
work your way shallower. The medical community
recommends avoiding going from shallow to deep
because there’s little test data about this kind of diving. Minor up and down variations (a few metres/feet)
are not likely an issue, but there are some theoretical
concerns if a successive dive is significantly deeper
than a previous dive. Note that if you accidently don’t
follow this guideline, for safety, dive computers still
provide no stop times.
6. Stay well within computer limits. Always try to
have five or more minutes no decompression time
remaining. If you let it near or reach zero, you’ve
pushed the limits even though you’ll have plenty of no
stop time when you ascend to a shallower depth.
7. If your computer quits, you may need to stop
diving for 12 to 24 hours. If it quits during a dive
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QUIZ
HELP
Self Assessment 4
1. Procedures for diving with a computer include (check all that apply):
a. sharing a computer with no more
than one other diver.
b. following the most conservative
computer — yours or your buddy’s.
c. keeping your computer turned on
between all dives.
d. making your deepest dive first,
and each subsequent dive progressively shallower.
2. Any dive that your computer provides no decompression dive time
for is acceptable.
True
False
How’d you do?
1. b, c, d. 2. False. Your computer may
provide data for dives that aren’t recommended.
Think.
Don’t blindly accept everything your computer says,
especially when it appears way out of line with a
buddy’s computer or your previous experience. Read
the manufacturer’s instructions completely before
using your computer, and follow what they say.
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and you’ve been staying well within the no decompression
limits, ascend immediately to 5 metres/15 feet, make a
safety stop for five minutes or more and surface. You can’t
simply grab another computer because it won’t know how
much residual nitrogen you have. Follow the manufacturer’s
instructions.
8. Take the RDP with you when you go diving.
Although computer failure has become vary, very rare, it still
happens once in awhile. If you’ve been noting your depths
and times (in your logbook, perhaps) and your dives have
been RDP limits, you can continue diving using the RDP.
Otherwise, you’ll probably have to wait until the next day for
residual nitrogen to clear before you resume diving.
Although it’s common for dive resorts to have scuba equipment including regulators and computers that you can rent
in case of a problem, that’s not always the case. Take your
RDP so you don’t miss out. Many active divers invest in a
second computer (and other gear) so there’s a spare for
themselves or a partner.
9. Keep thinking. Dive computers can fail just like any
other piece of equipment. Don’t blindly accept everything
your computer says, especially when it appears way out of
line with a buddy’s computer or your previous experience.
Read the manufacturer’s instructions completely before
using your computer, and follow what they say. You can learn
more about the theory and use of dive computers in the
PADI Multilevel Diver course.
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Underline/highlight the answers
to these questions as you read:
11. What are the four basic features of an underwater compass?
12. What is the proper hand and
arm position when using a
compass mounted on the
wrist?
13. What is the proper method of
holding a compass when it is
mounted in an instrument
console?
14. How do you set an underwater compass to navigate a
straight line from a beginning
location to a predetermined
destination?
15. How do you set an underwater compass for a reciprocal
heading?
Basic Compass Navigation
Navigation can seem pretty overwhelming when you consider that you’re trying to keep up with where the rest of the
world is. And that’s without mentioning how it feels to get
lost and realize you just lost track of an entire planet. By
learning to navigate underwater you’ll minimize how often
you get disoriented, and if it does happen, you’ll more
quickly figure out where you mislaid the whole of existence.
Don’t let it intimidate you – there are two kinds of divers:
those who have been lost underwater, and those who won’t
admit it.
Basic Compass
Navigation
See the PADI Underwater
Navigator Manual
Chapter Five
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Navigation makes your underwater adventure more
fun in several ways. It lets you plan your dive so
you don’t waste time and air trying to find the best
parts of the reef, and so you end your dive near
your exit point with ample reserve air left. By
knowing where you are at all times, you can head
straight for the boat or shore if a problem crops up,
and you know where you haven’t explored yet. If
there’s anything in the area you want to avoid, navigation helps you do so. Compass navigation helps
you swim a straight line — when you’re lost, you
tend to swim in a circle.
Follow me.
With experience you’ll learn to navigate by
following cues you find in the environment,
but an underwater compass makes navigating
easier and more accurate, and the more you
use it, the more true this is.
Index Marks
Magnetic North
Needle
Bezel
Lubber
Line
Basic underwater compass features.
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With experience you’ll learn to navigate by following cues you find in the environment (a diver who
has been there a gazillion times is a great cue to
follow), but an underwater compass makes navigating easier and more accurate, and the more you use
it, the more true this is.
Basically, compass navigation works like this: Your
compass remembers where the North Pole is, and
you remember where everything is in relation to
the North Pole. Okay, more detail will help, but
that’s the essential principle of compass navigation.
Let’s start with the four basic features you’ll find on
most underwater compasses:
1. Lubber line: The lubber line indicates your travel
direction and runs straight down the center of
your compass. It may be imaginary – you draw
the line mentally through the 0 degree and 180
degree marks. Or, the compass may have an
actual line there or along one side of the compass. Any time you navigate with your compass,
you have the lubber line pointed where you’re
headed, or you’re using the compass to point the
lubber line in the direction you should head. If
you’re navigating with your compass and you’re
not traveling along the lubber line, then . . .well,
then you’re not actually navigating with your
compass.
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2. Magnetic north needle: In the center of the compass is a needle (or an arrow printed on a disk)
that is free to rotate inside the compass. This
magnetic north needle, or compass needle,
always points to magnetic north. By doing this, it
creates an angle with the lubber line that you
use to maintain a straight line as you swim.
Center and level.
Hold the compass so the
lubber line aligns with the
center line of your body. On
your wrist, hold the arm
without the compass straight
out and grasp it with your
opposite hand near or above
the elbow, solidly placing the
compass in front of you.
If your compass rides in
your console, hold the
console squarely in front
with both hands.
3. Bezel: Most underwater compasses have a rotating bezel. To set the compass, align the two
small, parallel index marks on the bezel over the
compass needle. These help you maintain a
straight direction of travel.
4. Heading References: Most underwater compasses
have numbers so you can record your heading
(your direction of travel as measured in degrees
from magnetic north). A few compasses have
only general markings for north, south, east and
west; you can use these for general navigation,
but for precision you’ll want one with degree
headings.
Electronic compasses provide the same information
and functions, but use digital readouts. See the
manufacturer instructions if you’re using an underwater electronic compass.
To navigate with a compass, the first step is to hold
it correctly. Hold the compass so the lubber line
aligns with the center line of your body. If you wear
your compass on your wrist, hold the arm without
the compass straight out and grasp it with your
opposite hand near or above the elbow, solidly placing the compass in front of you. If your compass
rides in your console, hold the console squarely in
front with both hands.
When using your compass, keep the lubber line
aligned with your body center line. Otherwise you
won’t swim along the lubber line, and you’ll throw
off your navigation even if you use the compass correctly in all other respects.
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To navigate a straight line, simply point the lubber line in the
direction you want to go and align your body with the lubber
line. Hold the compass reasonably level (otherwise the needle
locks) and allow the needle to settle. Next, turn the bezel so the
index marks align over the compass needle. (For swimming in a
straight line, you don’t need to use heading degrees or north,
Lubber line leads.
To navigate a straight line,
point the lubber line in the
direction you want to go and
allow the needle to settle.
Next, turn the bezel so the
index marks align over the
compass needle. Travel along
the lubber line keeping the
needle within the marks.
south, east and west.)
Now, swim along the lubber line (your desired direction of travel)
while keeping the compass level and the needle within the index
marks. If the needle begins to leave the index marks, you’re turning off course. Adjust your direction so the needle stays within
the index marks. Remember that the compass needle never
really turns — it always points to magnetic north. If the needle
appears to have moved, it’s you who moved from the course.
Back where you
came from.
Now let’s set the compass for a reciprocal heading. First turn the
bezel so the index marks are exactly opposite their original location on the compass face. Next, turn until the compass needle
sits inside the index marks again. You now face the direction you
came from. Swim along the lubber line keeping the needle within
the marks like you did on the way out.
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To set the compass for a
reciprocal heading, if your
compass has only one set,
you rotate them 180º from
your original heading. Some
compasses have two sets of
index marks (as shown) with
the extra pair in place for a
reciprocal heading. Either way,
turn until the compass needle
sits inside the index marks
180º from your original
heading. You now face the
direction you came from.
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For diving in many environments, you’ll use the
compass to swim out, then set a reciprocal heading
to return to the boat or shore at the end of the dive.
With a little practice, you’ll find compass navigation
not only useful, but a fun challenge — it’s the kind
of skill that’s pretty easy to get down the basics you
need, but takes a lot of practice and experience to
attain the to-the-metre/foot precision that sets the
master apart from the average.
Even if you’re not into it for its own sake, you need
rudimentary navigation skills. Besides what you’ll
practice in this course, you develop your navigation
skills by making a point of using them when you
dive, and you can participate in navigation
Adventure Dives with your instructor. You can also
spend a fun weekend diving and learning about
navigation in the Underwater Navigator course, and
in the Advanced Open Water program.
Continuing Your Adventure
You’re not far from becoming a PADI Open Water
Diver, and you’re probably pretty focused on that
goal. Soon you’ll be a certified diver, inside the
threshold of diving, looking at all the adventure
diving offers.
Then what?
Q
Q
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HELP
Self Assessment 5
1. Basic features of an underwater
compass include (check all that
apply):
a. lubber line.
b. compass needle.
c. index marks.
d. bezel.
2. When using a compass, you want
to align your body center line with:
a. the compass needle.
b. the index marks.
c. the bezel.
d. None of the above.
3. To navigate a straight line, point the
______________ in your travel
direction and then put the
__________ over the __________.
4. To navigate a reciprocal
heading, rotate the bezel so the
_______________ are/is exactly
opposite the initial heading.
How’d you do?
1. a, b, c, d. 2. d. You align your body
with the lubber line. 3. lubber line,
index marks, compass needle.
4. index marks
Nav wizard.
Besides what you’ll practice in this
course, you develop your navigation
skills by making a point of using them
when you dive, and you can participate
in navigation Adventure Dives with
your instructor.
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Summary Points
In the subsections on Using a Dive
Computer and Basic Compass Navigation,
you learned:
▲ You should have your own computer
while diving — don’t try to share one.
▲ Keep your computer turned on all
the time.
▲ The dive medical community recommends that you make your deepest
dive first and plan successive dives to
progressively shallower depths.
Maybe it’s time you think about it. It’s such
a loss when a diver becomes certified and then
. . . and then nothing. No adventure. No challenge. It’s like someone hands the diver a new
world, and not knowing what to do with it, the
diver says, “No thank you,” and walks away.
Surely you didn’t take the time and effort to
earn your certification just so you can say,
“been there, done that.” But you may not
know where to go, or what to do with this new
world at your grasp. So let’s look at what you
need to do now so that when you look back in
a year, or ten, you won’t look back on “. . . and
then nothing.” You need to: 1. meet people,
2. go places and 3. do things.
▲ Stay well within computer limits.
Meet People.
▲ Back up your computer with dive
tables.
▲ Underwater navigation skills add to
dive fun and safety.
▲ The compass lubber line always indicates your travel direction; the compass needle always points north.
.
Since you can’t dive alone, the more diving
friends you have, the more dive opportunities
you’ll have. Not having someone to dive with
is one of the most common reasons why some
divers don’t keep diving after getting certified.
Maybe you already have friends who dive, but
if you don’t or
want more, what
do you do?
You’re off to a good start, if you think
about it. Don’t leave your final confined water dive and open water dive
for this course without getting the
name, telephone number and address
for everyone in the class. You know
these divers, and like you, they want
someone to dive with.
Next, join a dive club. Your PADI Dive
Center or Resort probably has one or
knows of one, which is probably a local
chapter of the PADI Diving Society
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Underline/highlight the answers to
these questions as you read:
16. What is the purpose of the
PADI System of diver education?
17. What are three benefits of
continuing your diver education beyond PADI Open Water
Diver?
18. What dive adventure do you
want next?
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ties, dives, events and other dive-related fun — and
you’ll meet other people to dive with. Don’t worry
that you’re new to diving — every dive group has
members at all experience levels and they plan
activities accordingly.
Go Places.
People like you.
Your PADI Dive Center or Resort probably has a dive
club or knows of one. Most of these organizations
coordinate activities, dives, events and other diverelated fun — and you’ll meet other people to
dive with.
A great way to meet people is to go on a dive trip
organized by your PADI Dive Center or Resort.
Plus, it takes you diving — which is what you’re
trying to accomplish. Although an exotic dive destination has the most appeal, don’t let time and
money limit your thinking. Most dive operations
offer local dive adventures close to home — and you
may be surprised just how much fun you can have.
Do Things.
Diving isn’t just about swimming around underwater sightseeing.
Diving should be personal. It’s about gaining the skills you need to
visit new dive sites you want to see. It’s about having the gear you
want so that diving takes you on the adventures that you think
worthwhile, so that it presents you with the challenges that you
think deserving, and so that diving grows with you and always
rewards you.
Only you can say whether this means taking on artistic challenges
like underwater photography and videography, skill challenges like
navigating or finding and recovering lost objects, or technical challenges like deep diving or enriched air diving. But recognize that
scuba diving isn’t an activity, but a door through which you reach
hundreds of underwater pursuits. Find those that ignite your
heart, and you’ll experience that which eludes many people — a
burning passion for what you do.
The PADI System of Diver Education
Looking at a flow chart for the PADI System of diver education,
one might conclude that its purpose is to take you to Master Scuba
Diver, or to PADI Open Water Scuba Instructor. But that’s not it
at all.
Becoming a PADI Master Scuba Diver, or Divemaster, or Instructor,
or whatever isn’t the purpose of the system, but a result of achiev-
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ing its purpose. The purpose of the PADI System is to provide the
means by which you 1. meet dive people, 2. go places diving, and 3.
do things underwater. Sound familiar?
Continuing your education beyond Open Water Diver has some tangible benefits — doing so introduces you to specialized dive activities. It gets you acquainted with diving in different conditions, and
it may get you diving in a wide variety of aquatic environments.
But again, these all lead back to the primary purpose of helping
you get out of diving what you got into diving for.
You’ll find that other PADI courses differ from this course. Many —
especially those that focus on adventure activities — take only a
day or two, and they’re mostly diving, with little or no classroom
work. Others, like the leadership level PADI Divemaster and Open
Water Scuba Instructor courses are much longer and more involved
— but as with many things, the rewards reflect
the effort and commitment required. Yet other
programs are but a single dive.
Choose from many.
Recognize that scuba diving isn’t an activity, but
a door through which you reach hundreds of
underwater pursuits. Find those that ignite your
heart, and you’ll experience that which eludes many
people — a burning passion for what you do.
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Regardless, by continuing to learn, you meet and get to know other
divers. You visit new dive sites (perhaps including dive travel), and
you get to try new activities and to develop new skills, helping you
find the aspects of diving that mean the most to you. Related to
this, you see what types of equipment best suit your preferences
and interests.
In other words, it assures that you meet people, go places and
do things.
PADI Adventure Dives. What’s it like to dive to 30 metres/100 feet?
How hard is it to shoot a camera underwater? Is night diving as
scary as it sounds?
You get the answers to questions like these by going on PADI
Adventure Dives, which introduce you to the basics of special
underwater activities. It’s a great way to see what interests you,
whether it’s deep diving, night diving, wreck diving, and so on. Your
instructor shows you what you need to know during a predive
briefing and review, and then you’re off doing it. The best part is,
it’s fun.
Adventures in Diving Program. Know what they call someone
who’s made five Adventure Dives? A PADI Advanced Open Water
Diver. You make an underwater navigation dive and a deep dive,
plus three other Adventure Dives that appeal to you. The background info you need you cover by reading short chapters in
Adventures in Diving and during some predive briefings, but as
with Adventure Dives, what you really do is meet divers, go places
diving and do new things underwater. You can earn the Advanced
Open Water Diver certification over time by going on Adventure
Dives, or you usually can sign up for it as a program. It usually
takes a weekend, but the schedule is incredibly flexible. Some people have done it in afternoons after work.
If you can’t complete all five Adventure Dives you need for the
PADI Advanced Open Water Diver certification, you can still earn
the PADI Adventure Diver rating after completing any three
Adventure Dives. PADI Adventure Diver certification dives can be
completed in just one day.
Specialty Diver Courses. Once you start figuring out what types
of diving you love, PADI Specialty Diver courses get you off on the
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right foot. In most of these programs you cover background
materials by doing a bit of reading, watching some exciting and
informative videos and discussing concepts in predive briefings.
Then you make two to four dives in the activity. PADI Specialty
Diver courses cover underwater photography, night diving, deep
diving, wreck diving, equipment, underwater navigation, search
and recovery, ice diving, cavern diving, altitude diving, boat diving, enriched air (nitrox), drift diving, dry suit diving, multilevel diving, underwater nature and more. Surely more than
one gets your pulse up.
And even better: The Advanced Open Water program
Adventure Dive happens to be the first dive of many PADI specialty courses. So if you try, say, a dry suit Adventure Dive (by
itself or as part of an Advanced Open Water Diver course) and
decide that you just have to have a dry suit and finish the
whole course, you’ve already got the first course dive under
your weight belt (at the instructor’s discretion).
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Keeps you diving.
The purpose of the PADI
System is to provide the
means by which you 1.
meet dive people, 2. go
places diving, and 3. do
things underwater.
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It works the other way, too. If you know now that you love,
say, underwater photography and go straight into the
Underwater Photographer course (which is a really great program, by the way . . . but we digress), the first dive from the
course counts toward your Advanced
Open Water certification (at the
instructor’s discretion).
Discover Local Diving. Not a course,
and you already know about this
from the discussion on getting a
local orientation when diving in a
new area. The Discover Local Diving
experience provides a single, supervised open-water experience to some
place new, with a briefing covering
local conditions, hazards and points
of interest, as well as an orientation to special procedures and
techniques used in the area. During the dive, you’ll see some
of the interesting points, as well as the potential hazards to
avoid. It’s a good way to plug into the local dive community
when you go some place new, and find out what activities suit
the local environment. Meet people, go places and do things.
Good things
to know.
The Rescue Diver course
refines and further develops
your accident prevention and
handling skills, plus teaches
you to manage an emergency.
Scuba Review. Ditto, you already learned about this, but it’s
worth a reminder: If you go several months or longer without
diving (it happens, best laid plans notwithstanding), you’ll
want to brush up your dive skills and knowledge. In Scuba
Review, you complete some short self-study (with a workbook
or CD-ROM) and review it with a PADI Divemaster, Assistant
Instructor or Instructor. Then you make a confined water dive
to put the polish back on your skills. Usually takes only a couple hours — easy way to limber up mentally and physically
for diving.
Rescue Diver Course. Serious fun. You learn a pile of skills,
most of which you hope you’ll never use. It’s a demanding and
challenging course. You’ll love it. Virtually all who take this
course cite it as one of the most rewarding courses they’ve
taken. Though challenging, you don’t have to be an athlete –
you learn rescue techniques suited to your physical characteristics and fitness level – what works for you.
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During the Rescue Diver course you learn to refine and further
develop your accident prevention and handling skills, plus
learn to manage an emergency if you’re ever faced with one.
Good things to know.
Emergency First Response. Like the Rescue Diver course, in
the Emergency First Response program you learn skills you
hope you never need, but will be glad you did if you ever do.
Emergency First Response combines CPR and first aid into a
single course, teaching you (at a lay level) the same emergency
protocols used by paramedics and doctors. Your nondiving
friends can take this course with you, and it can make a big
difference — even when you’re not diving.
Master Scuba Diver. The PADI Master Scuba
Diver rating is the highest nonprofessional
rating in recreational diving. This prestigious
rating means you’ve developed skills and
experience in a broad number of dive activities and environments. What makes a Master
Scuba Diver? Earn the PADI Advanced Open
Water Diver, the PADI Rescue Diver and five
PADI Specialty Diver certifications.
Rewards = efforts.
It takes effort and
commitment to become a
PADI Open Water Scuba
Instructor, but it is as
rewarding as it is
demanding.
Turn Pro. At some point, you may decide to make diving a full
or part time profession. For a lot of people, it beats working at
a desk, and if you love working at a desk, you can still turn
pro. Does all this seem too far off? No worries — you don’t need
to look this far ahead yet. But this will give you some idea how
your instructor and the instructor’s staff got where they are.
After Rescue Diver, your next step is PADI Divemaster. During
the Divemaster course, you sharpen your dive skills to demonstration quality, develop a professional-level understanding of
dive theory, learn to organize and conduct diving activities, and
learn how to assist with divers in training.
After Divemaster comes the PADI Assistant Instructor course.
The Assistant Instructor course begins developing the basic
knowledge and skills needed to teach diving. Next, you attend
a PADI Open Water Scuba Instructor Course (OWSI). In this
instructor-training course, you learn how to teach scuba diving.
After completing the OWSI course, you must pass a two-day
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Instructor Examination (IE) conducted by one of PADI’s
world wide offices. After completing the IE successfully,
you’re certified as a PADI Open Water Scuba Instructor —
the most in-demand dive professional in the dive community.
It takes effort and commitment to become a PADI Open
Water Scuba Instructor, but each step rewards you — and
you’re diving. Meeting people. Going places. Doing things.
Some Hard Truths About Diving
Before everything begins to sound too perfect, walk with open
eyes about diving and being a diver:
1. You’ll have dive experiences you don’t like. Count on it.
The conditions will not be good, you won’t like the boat, you’ll
choose a buddy you don’t like, you won’t like the area you’re
visiting, or you’ll find you don’t like the particular activity
you’re trying. But guess what: If you play golf, you’ll slice the
ball off the course. If you ride horses, one will step on your foot.
If you ski, you’ll fling yourself face first into a snow bank. If
you play chess, some whiz kid will checkmate you in 12 moves.
Everything worth doing has its less-than-love-it moments.
Don’t let a bad day of diving ruin diving for you. Learn from it
and do it differently next time. Pursue what you want out of
diving and progress in diving at your rate, and you’ll have many,
many great dive memories for each one you’d rather forget.
2. It’s better to have your own gear. It really is. Divers who
own their own equipment dive more often and dive more comfortably. They avoid the hassles of fitting into rental gear every
time they go.
This isn’t to say you need to drop everything and go get set up
head-to-toe in gear at this moment (but if you want to, go for
it). However, keep it in mind and begin investing as your budget and dive activity can accommodate.
3. You get out of diving what you put into it. You’ve just
read about a lot of different things you can do underwater, and
there are others not mentioned. If you ever find yourself bored
with diving, you need to look closely at what you want out of
diving, and what you’re doing. If you’re not satisfied, you need
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to turn your diving in a new direction. There are
people who have made more than 1000 dives over
more than 30 years – and they’re still meeting
new people. Going new places. Doing new things.
Only you can make yourself reach for what’s new
and exciting in diving.
Your Next Dive Adventure
Okay, so you won’t look back in a year and wonder why you haven’t been diving, before you finish this course, go to your PADI Dive Center or
Resort and do one or more of the following:
1. Sign up for a dive trip.
2. Sign up for a local dive with the store or the
store’s dive club/Diving Society Chapter.
3. Sign up for a PADI specialty course, Advanced
Open Water course, or Adventure Dive.
4. Invest in a regulator/BCD package, or exposure suit package.
Do not leave until you do one of these. No
joke — because research shows that people who
do one of these when they finish their Open
Water Diver course are more likely to get out of
diving what they got into diving for. Plan your
next step now.
M eet people.
G o places.
D o things.
U nderwater.
Using the Recreational
Dive Planner (Continued)
Finish the rest of the Instructions for Use booklet
that comes with your RDP.
Then come back to this manual and pick up with
the Confined Water Dive Preview.
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UICK
Q
QUIZ
HELP
Self Assessment 6
1. What dive adventure do you want next?
Answer: Your choice — but choose, or . . .
or nothing.
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By the time you complete the
assigned reading in Instructions
for Use booklet assignment for
the RDP (Table or Wheel), you
should be able to answer the following questions:
19. How do you find the minimum
surface interval required to
complete a series of no
decompression dives using
the Recreational Dive Planner?
20. How do you plan a multilevel
dive with The Wheel? [The
Wheel only.]
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Dive Tables Definitions
You’ve learned the following terms in the discussions on dive computers and in learning to use
the RDP (if you learned to use The Wheel, you
may not have run into some of these because
you don’t need them with The Wheel). This list
provides a convenient and quick reference
and review.
Actual Bottom Time (ABT) — In repetitive
diving, the total time actually spent under water
(in minutes) from the beginning of descent until
leaving the bottom for a direct continuous ascent
to the surface or safety stop.
Adjusted No Decompression Limit — The
time limit for a repetitive dive that accounts for
residual nitrogen. Found on Table 3 of the RDP
Table; The Wheel automatically adjusts for residual nitrogen. Actual Bottom Time should never
exceed the adjusted no decompression limit.
Ascent Rate — The proper speed for ascending,
which is no faster than 18 metres/60 feet per
minute. A rate slower is acceptable, and
appropriate.
The PADI
Diving Society
The PADI Diving Society is an
organization for people like you –
scuba divers, snorkelers and other
water enthusiasts. Emphasizing the
diving lifestyle, the Society connects you with what’s happening
underwater, by the water and on
the water. PADI Diving Society
member benefits vary to fit the different needs divers have around
the world, but include travel advantages, involvement with environmental efforts, and the official
Diving Society publication, Sport
Diver.
The PADI Diving Society immerses
you in the diving lifestyle. See your
PADI Dive Center, Resort or
Instructor about diving into it.
Bottom Time — The time from the beginning of
descent until the beginning of a direct, continuous ascent to the surface or safety stop.
Decompression Diving — Diving that requires
planning stops during ascent to avoid decompression sickness. In recreational diving (no decompression diving), a decompression stop is considered an emergency procedure only, and is never
an intentional part of the dive plan.
Dive Profile — A drawing of your dive plan,
used to avoid confusion and omissions when
using the dive tables.
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Multilevel Diving — Planning profiles that credit you for slower nitrogen absorption when you ascend to a shallower depth. This provides
more no-stop dive time. The Wheel version of the Recreational Dive
Planner can be used for multilevel diving.
No decompression Limit (NDL) — The maximum time that can be
spent at a depth before decompression stops are required. Also called
“no-stop time.”
No-Stop Dive — A dive made within no decompression limits because you don’t have any required
emergency decompression stops.
Pressure Group — A letter used on the
Recreational Dive Planner to designate the amount
of theoretical residual nitrogen in your body.
Repetitive Dive — A dive that follows another while there’s still a significant amount of residual nitrogen in your body. Using the Recreational
Dive Planner, this is a dive made within six hours of a previous dive.
Residual Nitrogen — The higher-than-normal amount of nitrogen
remaining in your body after a dive.
Residual Nitrogen Time (RNT) — An amount of nitrogen, expressed
in minutes (found on Table 3 by using a pressure group letter) for a specific depth, that you add to the actual bottom time of a dive to account
for residual nitrogen from a previous dive. Not needed with The Wheel.
Safety Stop — A stop made between 3 and 6 metres/10-20 feet — usually 5 metres/15 feet for three or more minutes at the end of a dive for
additional safety. The safety stop is recommended after all dives (air supply and other considerations allowing), and required on those to 30
metres/100 feet or greater, and those coming within three pressure
groups of the no decompression limit.
Surface Interval (SI)— The amount of time spent on the surface
between two dives. It is usually recorded in hours:minutes (e.g. 3:25 — 3
hours, 25 minutes).
Total Bottom Time (TBT) — The sum of Residual Nitrogen Time and
Actual Bottom Time after a repetitive dive, used on Table 1 to determine
the pressure group. Not needed with The Wheel.
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Confined Water Dive Preview
This is the last confined water dive in the Open Water Diver course. As
in the previous sessions, you’ll practice skills you’ve already learned, and
learn some new ones.
Weight System Handling
There may be times when you’ll need to remove or replace your weight
system on the surface or underwater. Your weight belt may have become
tangled with other equipment, you may need to adjust your gear, or you
may need to take it off before entering small boats or climbing onto a
platform without a ladder.
To remove a weight belt, release the
buckle with one hand and grasp the
free end, like you did during Confined
Water Dive Three, pulling it clear of
your body. Since you’re not ditching
the belt, keep it close to your body
because holding it away tends to pull
you over in the water. If you were
ditching it, you would hold it well
away before letting go. Keep in mind
that once you release your weight belt,
your center of buoyancy changes and
you’ll probably feel yourself trying to
orient differently in the water. When
working with your weight belt,
remember to hold the free end (the
end without the buckle) so the weights
can’t slide off.
Whether you’re at the surface or on
the bottom, you can use two methods
to replace a weight belt. Breathe
through your regulator even if you’re
at the surface so you can maneuver in
the water without having to worry
about flooding your snorkel.
Confined Water
Dive Five
Skill Requirements
Here’s what you’ll be able to do when
you successfully complete Confined
Water Dive Five:
1. Remove, replace, adjust and
secure the scuba unit and weights
at the surface, with minimal assistance, in water too deep to stand
up in.
2. Remove, replace, adjust and
secure the scuba unit on the bottom, with minimal assistance, in
water too deep to stand up in.
3. Remove, replace, adjust and
secure weight belt on the bottom in
water too deep to stand in, or for
students using weight integrated
BCDs or weight harness systems,
in shallow water, remove weights
while underwater.
To use the first method, stretch out
horizontally face up. Hold the free end
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of the belt in your right hand and place it
against your right hip. Now roll to the left
so you’re face down. Your weight belt
should roll around your hips and fall into
place across your waist, though you may
have to guide it under your tank. Lean forward slightly, and the belt will slide into
the small of your back. Allow the weight to
drape across your back, check for twists,
push any misadjusted weights into place
and secure the buckle.
Roll on.
To don a weight belt using the roll method, hold
the free end in your right hand and place it against
your right hip. Roll to the left so you’re face down
and the belt should roll around your hips and fall
into place across your waist.
For the second method, hold both the free
end and the buckle end in one hand so the
belt forms a loop. Reach with the belt
behind yourself, below your tank, and with
your free hand, take one end so both hands have an end. Be sure that
your right hand ends up with the free end and your left hand ends up
with the buckle so you have a right-hand release when you’re done.
Once you have an end in each hand, lie horizontal face-down and drape
the belt across the small of your back while you adjust and buckle it.
With either method, you’ll probably find that your mask and BCD
interfere with seeing the buckle while you’re trying to release or fasten
it. Practice operating the buckle by
touch, rather than by sight.
If you’re using a weight integrated
BCD, for the purposes of disentangling, adjusting, etc., removing and
replacing your scuba unit accomplishes removing and replacing
your weights. To provide practice in
using your emergency release system, your instructor will have you
release your weights using your
quick release in shallow water.
Scuba Unit Handling
As with your weights, there may be
times when you remove and replace
your scuba unit. Underwater, your
scuba unit may need adjustment or
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Again, left gets it right.
To using the loop method, hold both the free end and the buckle
end in one hand so the belt forms a loop. Reach with the belt
behind yourself, below your tank, and with your free hand, take
one end so the buckle ends up in your left hand.
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may be slightly entangled and need to be
freed. On the surface, you may put your scuba
unit on after entering the water and (as you
may have already practiced) take it off
before exiting.
Left, right. Right, left.
You may find it easiest to remove and replace
your scuba unit like a sleeveless coat. Vent
all the air from your BCD, release the waist
strap and take your left arm out of the BCD
so you don’t pull the second stage out of
your mouth. To replace it, hold the unit
upright and be sure the straps are clear, then
put it on like a coat, starting with your right
arm. Once it’s in place, fasten and adjust the
waist strap and any other straps.
Underwater, you may find it easiest to remove
and replace your scuba unit like a sleeveless
coat. First, be sure to vent all the air from
your BCD so it won’t float away when you take
it off. Release the waist strap. Then take your
left arm out of the BCD, swing it behind you
and take it off your right arm. Be sure to start
with the left arm, or you’ll stretch the regulator hose and possibly pull it out of your mouth.
There’s no reason to take the second stage out
of your mouth during this skill.
After it’s off (you’ll find it easy to handle
because scuba tanks weigh very little in
water), you would adjust/untangle whatever
and then replace it.
Hold the unit upright
and be sure the straps are clear, then put it on
like a coat, starting with your right arm first
(same reason — so you don’t pull the second
stage out of your mouth). Once it’s in place, fasten
and adjust the waist strap and any other straps.
You can also put it back on over your head. Lay
the unit in front of you, with the valve toward
you and the jacket facing up. Put your arms in
the jacket up past your elbows. Keep the hose to
your mouthpiece between your arms (if it is outside your arms, you’ll pull the second stage out
of your mouth as you swing it overhead). Next,
raise the tank over your head and gently lower
the tank into place. Finally, make sure all your
hoses are clear before you fasten the waist strap.
You can follow the same procedure for removing
your scuba unit at the surface as you did underwater. A popular donning technique is to sit on
On over your head.
To don overhead, put the unit in front of you
with the valve toward you and the jacket
facing up. Put your arms in the jacket up past
your elbows. Keep the hose to your mouthpiece between your arms. Raise the tank over
your head and gently lower the tank into
place. Finally, make sure all your hoses are
clear before you fasten the waist strap.
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the slightly buoyant unit with the tank
between your legs. Put the bottom of the tank
in front of you, the valve behind you, and the
jacket open beneath you. Put your arms into
the jacket sleeves on each side, and then let
yourself slip forward. The unit slides up, you
slide down and presto! You’re in the jacket.
Open Water Dives 3, 4 and
Optional Skin Dive
Here’s a preview of the skills and procedures
you’ll practice during your second two Open
Water Dives. The sequence within each dive
will vary, depending on the logistics, and your
Open Water Dive 3
Overview
Briefing
Equipment preparation
Don and adjust equipment
Predive safety check
Entry
Buoyancy/weight check
(50 metre/yard straight line surface swim
with compass)*
Free descent with reference to 6-9 metres/
20-30 feet (max dive depth 18 m/60 ft)
Buoyancy control — neutral buoyancy on
bottom, fin pivot oral
Complete mask flood and clear
(CESA)*
Buddy breathing — stationary and ascent
from 6-9 metres/20-30 feet (optional)
Underwater exploration
Ascent
(Remove and replace weight system
at the surface)*
(Remove and replace scuba unit at
the surface)*
Exit
Debrief and log dive
Open Water Dive 4
Overview
instructor may sequence some skills in different dives. Before each dive, your instructor
will brief you about what you’re going to do
and when, along with other information you
need for the dive, like communication signals,
an environmental orientation, emergency procedures, safety rules, and so on.
There’s also an Optional Skin Dive, which
your instructor or an assistant will lead you
on if logistics permit. Your instructor will
schedule this for the most appropriate time
amid your scuba dives depending on logistics,
local conditions and your needs.
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Briefing
Equipment preparation
Don and adjust equipment
Predive safety check
Entry
Buoyancy/weight check
Free descent without reference no deeper
than 18 metres/60 feet
Buoyancy control — hovering
Mask removal, replacement and clearing
(Underwater navigation with compass)*
Underwater exploration
Ascent
Exit
Debrief and log dive
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Optional Skin Dive
Overview
Briefing
Equipment preparation
Suiting up
Equipment inspection
Entry
Buoyancy/weight check
Surface swim
Surface dives and underwater
swimming
Displacement snorkel clear
Underwater exploration
Exit
Debrief and log dive
Enriched Air Nitrox
In many areas, diving with enriched air nitrox has
become popular. Enriched air nitrox (a.k.a. enriched
air or EANx) is simply air with extra oxygen added to
it to decrease the proportion of nitrogen you breathe.
As you learned in Sections Four and Five, nitrogen
limits the amount of time you can spend at a given
depth, so enriched air lets you stay longer, all else
being equal, though it has some special considerations you need to be aware of. Your instructor may
give you the opportunity to try diving with EANx in
Open Water Dive Four, and you may credit this (at
your instructor’s discretion) toward the PADI
Enriched Air Diver certification.
* These skills may be sequenced in
other dives, depending on logistics.
Dive Safety Practices Summary
The following summarizes the safe diving practices you’ve learned
during this course. Review it periodically and keep them in mind
when diving.
Preparation
1. Stay healthy and fit for diving. Eat right, exercise regularly and
get adequate rest.
2. Have approval for diving from a physician who has given you a
thorough medical examination and have one every two years.
3. Be recently trained in first aid and cardiopulmonary resuscitation (CPR). To acquire training in these areas, take the
Emergency First Response program offered by PADI Instructors,
Dive Centers and Resorts.
4. Maintain your dive skills by diving as often as you can, by continuing your diver education. Refresh your knowledge and skills
with Scuba Review after long periods of inactivity.
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5. Get an orientation to new diving conditions, activities or areas.
When planning a dive in a new, unfamiliar area, participate in a
Discover Local Diving experience. Remember that you should have
special training for some activities.
6. Always have and use all the equipment needed for the conditions
and environment.
7. Have your scuba equipment serviced annually, or as recommended
by the manufacturer. Have scuba tanks visually inspected regularly and pressure tested at required intervals. Maintain your
equipment in good condition and inspect it before diving.
8. Only fill scuba tanks with pure, dry compressed air from reputable
air stations.
Predive
1. Dive only when feeling well, both physically and mentally. You
should feel confident about the dive. Be sure the dive and its activities are within your capabilities. Remember — diving is supposed
to be fun. If you don’t think it will be safe or fun, don’t make
the dive.
2. Know the dive site. Evaluate conditions and check for possible
hazards.
3. Check the weather forecast before diving. Evaluate the dive conditions, those present and expected, and dive only when the conditions are as good as or better than those in which you have experience and/or training. Don’t dive in poor conditions.
4. Refrain from alcohol, smoking or dangerous drugs before or immediately after diving.
5. Plan your dives with your buddy. Agree on objectives, direction,
and depth and time limits. Review underwater communications,
emergency procedures and what to do if you become separated.
6. Always plan for no decompression diving. Consult the Recreational
Dive Planner and allow for a margin of safety. Avoid diving to the
maximum time limits of the RDP or your computer. Make your
deepest dive of the day first. Know how to perform an emergency
decompression stop, but avoid having to do so. Plan to make safety
stops whenever possible. Be aware of the effects of flying after diving and diving at altitudes greater than 300 metres/1000 feet.
7. Inspect both your and your buddy’s equipment. Know how to operate each other’s equipment. Always conduct a predive safety check:
Begin With Review And Friend (BWRAF — BCD, Weights,
Releases, Air, Final okay).
8. Be prepared for emergencies. Have local emergency contact information on hand, just in case.
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Diving
1. Properly weight yourself for neutral buoyancy. Check your buoyancy at the surface and avoid being overweighted. If you check
buoyancy with a full cylinder, add enough weight to offset the air
you use (typically about 2.5 kg/5 lbs with a single cylinder).
2. Always wear a proper buoyancy control device (BCD). Use your
buoyancy control device to regulate your buoyancy. Avoid contact
with the bottom by staying neutrally buoyant — for your benefit
and the benefit of the aquatic environment. Inflate your BCD at
the surface to provide ample positive buoyancy.
3. Display the appropriate local dive flag and stay near it.
4. Begin dives against the current, and/or take into consideration the
effect the current will have during the dive. Plan your dive so you
don’t have to fight the current to reach your exit point.
5. Equalize pressure early and often during descents. If you feel
discomfort in a body air space, ascend until the discomfort goes
away, equalize, then continue the dive. If you can’t equalize, abort
the dive.
6. Stay with your buddy throughout the dive. Know how to reunite if
you accidentally separate.
7. Limit your depth to 18 metres/60 feet or less as a new diver.
Remember that 18 metres/60 feet is the recommended limit for
new divers. Shallower diving conserves your air, increases your
bottom time and helps reduce the risk of decompression sickness.
8. Spear guns are dangerous weapons. Do not load them out of water
and always unload them before leaving the water. Treat them
as though they’re always loaded – never point them at
another person.
9. Avoid contact with unfamiliar aquatic plants and animals.
10. Be alert for possible problems and avoid them. Check your equipment frequently while underwater, especially your gauges: depth
gauge, timing device and submersible pressure gauge, compass and
dive computer.
11. Exit the water with a minimum of 20-40 bar/300-500 psi in your
tank, or more if the dive plan or conditions warrant an extra margin of conservatism.
12. Pace yourself. Avoid overexertion and breathlessness. If you
become breathless, stop, rest and recover before proceeding.
13. Breathe properly — slowly, deeply and continuously. Never hold
your breath while scuba diving. Exhale slowly and continuously
any time the regulator is not in your mouth. Avoid excessive hyperventilation when skin (breath-hold) diving.
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14. In an emergency, stop, think, get control and then take action. Act
based on your training, don’t react based on instinct.
15. Ascend carefully and correctly. Reach up and look up during the
ascent. Come up no faster than 18 metres/60 feet per minute. Plan
a 3-minute safety stop at 5 metres/15 feet whenever possible.
Listen for boats as you come up, and establish buoyancy as soon as
you reach the surface. Be a S.A.F.E. Diver — Slowly Ascend From
Every dive.
16. Stop diving when you’re cold or tired. Don’t overextend yourself.
17. Stick to your dive plan underwater. Don’t revise a dive plan underwater.
18. Stay out of overhead environments unless you’re properly trained
and equipped for that overhead environment.
General Dive Safety Practices
1. Be an active diver. Dive frequently to maintain your proficiency.
2. Build your experience and capabilities gradually under safe conditions.
3. Keep a dive log. This records your training and experience and is a
valuable reference for future dives.
4. Don’t lend your equipment to untrained persons. Never attempt to
teach another person how to dive. Teaching diving requires specialized training and skills. Leave instruction to trained professionals.
5. Continue your diver education. Remember that a good diver never
stops learning.
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Knowledge Review—
Chapter 5
(Answer all questions, regardless of which Recreational Dive
Planner you are using — The Wheel or table version.)
1.
Describe the three required situations in which a safety stop should be made.
a. ____________________________________________________________________________
____________________________________________________________________________
b. ____________________________________________________________________________
____________________________________________________________________________
c. ____________________________________________________________________________
____________________________________________________________________________
2.
Check one. If you accidentally exceed a no-decompression limit or an adjusted nodecompression limit by no more than 5 minutes, you should slowly ascend at a rate
not faster than 18 metres/60 feet per minute to 5 metres/15 feet and remain there for
_____ minutes prior to surfacing. After reaching the surface, do not dive for at least
_____ hours.
a. 8 minutes, 6 hours
3.
b. 15 minutes, 24 hours
State the altitude (metres/feet) above which the Recreational Dive Planners should
not be used unless special procedures are followed.
____________ metres/feet
4.
True or False: To reasonably assure you remain symptom free from
decompression sickness when flying in a commercial jet airliner after diving,
wait 12 hours. ______________
5.
Explain the procedure you must follow when planning a dive in cold water or under
strenuous conditions using the Recreational Dive Planner.
6.
What is the minimum surface interval required between a dive to 18 metres/60 feet
for 40 minutes followed by a dive to 14 metres/50 feet for 60 minutes?
Minimum Surface Interval = ______________
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What is the minimum surface interval required between a dive to 20 metres/70 feet
for 29 minutes followed by a dive to 14 metres/50 feet for 39 minutes?
Minimum Surface Interval = ______________
8.
With reference to the compass heading shown in Figure 1, select the figure letter that
indicates a reciprocal heading.
Figure 1
A
B
C
Reciprocal heading is shown by figure letter: ______________
9.
What’s the purpose of the PADI System of continuing education?
10. What are the benefits of PADI Adventure Dives and the Advanced Open Water
program?
11. State the purpose of a PADI Discover Local Diving experience.
12. When should you consider taking a PADI Scuba Review course?
13. What’s the relationship between Adventure Dives, Advanced Open Water Diver
course dives and Specialty Diver courses?
Student Diver Statement: I’ve completed this Knowledge Review to the best of my ability,
and any questions I answered incorrectly or incompletely I’ve had explained to me, and I
understand what I missed.
Name ________________________________________________ Date ________________________
Knowledge Reviews may not be reproduced in any form without the written permission of the publisher.
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