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From
Scuba Diving Magazine's April 2002 issue...
Dive Better, Dive
Safer: 101 Tips that'll make you a Pro
You're a good diver. You
could be better. Here's how.
Hit the Pause Button 4
Times
Get in the habit of
inserting pauses in your dive plan. It's a chance to
take stock, collect yourself and relax a moment.
-
After you're geared up, pause a moment:
Forget anything? Does everything feel right?
-
After you enter the water but before you
submerge: Is your weight belt still in place? Is your
buddy OK? Is there current?
-
After you reach max depth but before you
move off: How do you feel? Check your equipment, check
your gauges, check your buoyancy, check your buddy. Look
around so you can recognize the scene when you return
and are trying to find the anchor line.
-
After you finish your safety stop but
before you surface: Hear any propellers? Check your
buoyancy.
6 Tips for Better
Buoyancy Control
-
Minimize your weighting. Extra air in
your BC, to support extra lead on your belt, will change
volume and buoyancy with depth, causing you to yo-yo and
preventing you from maintaining neutral buoyancy.
-
Check it at the safety stop. It's at the
end of your dive, not the beginning, that you should be
weighted for neutral buoyancy at 15 feet. That means
you'll be about five pounds heavy at the beginning of
the dive. (That's the weight of the air you use.)
-
Suspend a weight bag. Hang a mesh bag
with some one-pound and two-pound weights from the boat
at about 15 feet. Start the dive with two pounds or so
of your weight in a BC pocket. At the safety stop, next
to the weight bag, you can transfer weights between
pocket and bag to find your perfect weighting.
-
Relax. To find neutral buoyancy, go limp.
Any sculling with hands or feet will create upward
thrust.
-
Add and subtract air in small squirts.
You must wait a minute for adjustments to take effect
before adding or subtracting more. The effect is not
instantaneous.
-
Use your lungs, not your BC. Make slight
temporary changes to your buoyancy by holding more or
less air in your lungs. That way you don't disturb the
correct inflation of your BC. Hold air with your chest,
not by closing your glottis, so pressure can escape.
17 Ways to Reduce Air
Consumption
-
Streamline your equipment. Stash
accessories in pockets or leave them behind. Reduce the
lengths of your hoses where you can and route them close
to your body. Clip in your console and your octopus.
Choose a BC sized properly for your body and for the
buoyancy you need; too much causes excess drag.
-
Drop weight. The less weight you carry,
the less air you have to put into your BC to maintain
buoyancy, so the less bulk you have to drag through the
water. You use more air dragging more bulk around. Most
divers can drop two pounds or so.
-
Get neutral. And get trimmed properly, so
that when you're neutral, you're horizontal. That
minimizes the size of the "hole" you have to make in the
water when you swim.
-
Move slowly. Water resistance increases
exponentially with speed. Swimming twice as fast
requires four times as much energy. All your movements
should be in slow motion.
-
Kick within your slipstream. Keep your
fins within that "hole" in the water made by your body.
Wider kicks increase drag.
-
Use efficient fins. Some deliver more
thrust for a given effort than others, especially split
fins.
-
Don't skim the bottom. Both the bottom
and the surface cause turbulence that robs energy if you
swim within a few feet of them.
-
Make long surface swims on your back. And
breathe surface air: It's free.
-
Pause after inhaling. Under water, your
breathing pattern should be inhale, pause, exhale,
inhale, pause, exhale. The pause (held with your chest
muscles, not by closing your throat) allows more gas
transfer to take place in your lungs and less oxygen to
be wasted.
-
Breathe slowly. Friction between the
incoming air and your mouth, throat, lungs, etc.
increases exponentially with speed. More friction means
more energy expended for less air actually arriving in
your lungs. Move the air slowly.
-
Breathe deeply. The more complete each
breath is, the fewer of them you have to take. Breathe
"from the diaphragm," trying to completely fill and
completely empty your lungs.
-
Use a high-performance regulator. Better
regulators minimize the work of breathing. They minimize
the amount of air you burn just getting air.
-
Maintain your regulator. They lose
performance and increase work of breathing with use and
age, and need regular maintenance.
-
Readjust your regulator. On many
regulators, the purpose of the adjustment knob is not
merely to prevent free-flowing on the surface. It's also
to minimize work of breathing at depth. Periodically
during your dive, open the valve until the regulator
just begins to bubble, then back up on the adjustment a
bit.
-
Stop all leaks. Lots of little bubbles
add up. Usual suspects: tank O-ring, BC inflators,
console swivels.
-
Stay above. At five feet less depth than
your buddy, you'll see almost everything he does, but
you'll use substantially less air. (Though the
difference is greatest at shallower depths.)
-
Manage currents wisely. Learn how to
detect, avoid and cope efficiently with adverse
currents.
4 Ways to Be a Better
Buddy
-
Communicate. Dive planning means talking.
Don't assume you both know what to do. Be explicit about
depth and time limits, buddy separation procedure, etc.
-
Two-way gear check. The gear check isn't
over when you've checked your buddy's gear. He or she
must check yours too. That forces your buddy to put
hands on the gear, to take responsibility for it being
correct. Likewise, make sure gauge checks during the
dive go both ways.
-
Take turns. During the dive, don't always
be the one who leads, because that trains your buddy to
be a follower. Make a point of trading off, so your
buddy takes as much responsibility as you for setting
the pace and direction.
-
Be humble. Admit you can be wrong. Don't
dismiss your buddy's warning/correction/suggestion out
of hand.
3 Tips for an
Out-of-Air Ascent
-
Relax. Easier said than done, but many
"out-of-air" emergencies are really cases of anxiety
causing the diver to overbreathe the regulator. Slow
your breathing, and you may find you have plenty of air
after all.
-
Keep your reg in your mouth. You may be
totally out of air at depth, but keep trying to breathe.
As you ascend and ambient pressure falls, more air will
probably become available from your tank.
-
Exhale slowly. The air in your lungs
expands as you ascend, and it's not uncommon to exhale
all the way up and reach the surface feeling you have
more air in your lungs than when you began the ascent.
5 Tips for Mapping a
Dive Site
-
Sketch the dive site on your slate.
Actually drawing it is a memory aid. It helps even if
you never look at it again.
-
Orient toward north. Draw the map so
north is at the top. Under water, lining up your slate
with your compass needle puts things in proper
orientation. Mark the direction of the sun and the
current, too.
-
Use navigational charts. Or other site
sketches to get the overall shape.
-
Listen to the dive briefing. Ask
questions about depths, trend of bottom and underwater
topography.
-
Use your eyes. Above-ground profiles
often extend under water; a cliff above is often a wall
below.
9 Ways to Minimize Your
DCS Risk
-
Ascend slowly. A slow ascent rate is a
"rolling" decompression stop that allows nitrogen to
offgas before it bubbles.
-
Make a safety stop. It's not called a
decompression stop, but that's what it is. It allows
more offgassing before you ascend through the final 15
feet, where pressure change per foot is greatest.
-
Don't exercise after diving. It seems to
increase formation of bubbles. "Like shaking a can of
soda," some people say.
-
End the dive shallow. When you are
ascending, you're offgassing from the faster tissues,
which are usually most critical for neurological DCS.
Time spent shallow at the end of the dive helps unload
the nitrogen taken on during the early, deeper parts.
-
Avoid sawtooth and bounce profiles. It's
believed that repeated ascents and descents increase the
chance of microbubbles passing to the arterial side of
your circulation.
-
Wait 24 hours before flying. Flying soon
after diving has the effect of making the dive deeper,
and bubble formation is greater.
-
Stay warm. If you're cold, your
circulation is restricted and nitrogen is passed off
more slowly.
-
Stay hydrated. If you're dehydrated, your
blood is thicker and moves more slowly, so offgassing is
slower.
-
Don't use all the green. Computer
algorithms are predictions, not guarantees. Back off a
"click" or two for more safety.
5 Compass Tips
-
Practice on land. Try walking around a
parking lot or a football field while looking mostly at
the compass. When you can return to your starting point,
you'll be better able to do the same under water.
-
Make sure the card rotates freely. If it
hangs up, the reading will be wrong. Check by rotating
the compass in your hand: The card should not move.
-
Fine-tune your buoyancy. Get in trim
before taking a compass reading. If you are fighting to
maintain your attitude, you will be more likely to get a
false reading.
-
Use the bezel. Rotate it to mark your
course. Checking your course requires only matching the
north arrow to the bezel mark (or something equally
simple, depending on the design of the compass).
-
Mount the compass on a slate. The slate
helps you level the compass and is handy for marking
bearings. Console mounts are often difficult to level
because of the stiff hose.
15 Seasickness Tips
HOW TO AVOID IT:
-
Pop a pill. All the pills are about the
same in effectiveness and side effects. But if one of
them—Dramamine, Bonine, Marazine, etc.—seems to work
better for you than the others, stick with it. The
placebo effect is very strong with seasickness.
-
Start taking pills early. Pills are
better prevention than treatment. After you feel queasy,
it may be too late for pills to help, so start 12 to 24
hours before going to sea. This builds up a level of the
drug in your body.
-
Try the patch ... Scopolamine patches do
work better than pills and have fewer side effects for
most people. They are available by doctor's
prescription.
-
... Or the bands. Some people like "Sea
Bands." They are bracelets with dots that purportedly
touch acupressure points on your wrist. They have never
been proven effective, but some people swear by them.
-
Bigger is better. Bigger, and especially
wider, boats have a slower roll than smaller ones.
-
Stay on deck. It helps to be able to see
the horizon, possibly because your eyes then agree with
what your middle ears are saying—that your body is
rocking and pitching. One theory is that nausea is
caused by mixed messages when, below decks, your eyes
report that all is stationary.
-
Don't try to read. Focusing your eyes on
an apparently stationary target makes them even more
convinced that your middle ears are wrong.
-
Close your eyes if you must go below. You
may have to go below and lie down, in which case you
should close your eyes so they aren't giving a no-motion
message to your brain.
-
Be clean and sober. Even a mild hangover
can easily degenerate into seasickness, besides
increasing various diving risks. Likewise, fatigue
predisposes you to seasickness.
-
Eat something. Opinions vary on this one,
but most people feel better with a little bland food on
their stomachs. Bread, bagels, pancakes, etc. are better
than eggs and bacon. Coffee and orange juice are acidic
and may irritate your stomach. Eat a little, not a lot.
-
Relax. Anxiety contributes to
seasickness. Those who are frightened by the ocean and
the movement of the boat, or anxious about the diving
later in the day, are more likely to become seasick.
-
Watch for symptoms. Early signs include
chills, headache and frequent burping. Now is the time
to go on deck, or move to the lee rail if you're already
there.
I'M SEASICK: NOW WHAT?
-
If you feel the urge, let it rip. You'll
feel better almost immediately. Prolonging the
inevitable only prolongs the pain.
-
Don't use a toilet. Or, God help us, a
trash can. Go to the rail on the lee (downwind) side or
use a bucket if one is designated. If you feel the urge
coming, ask a crew member where to go. He or she will
know the best place. Don't be embarrassed; you're not
the first.
-
Get over it. After a few hours, most
people feel better. For some it takes a day or two.
Almost everyone gets over seasickness within three days.
6 Ways to Stay Warm
-
Wear a hood. It should be the first piece
of thermal protection you consider, not the last. While
near-surface blood vessels elsewhere in your body close
down to minimize heat loss, those in your head continue
at full flow.
-
Stop the leaks. The best wetsuit or dry
suit is worthless if it lets in too much cold water.
Repair broken zippers and split seams. The collar seal
is especially important because as you swim forward it
tends to scoop in water. Wear a hood if for no other
reason than to seal the neck opening.
-
Cover up head to toe. Heat loss is huge
where cold water flows over bare skin, so a thin
full-length suit is warmer than a thicker shorty.
-
Stay shallow. Shallower depths mean the
insulating neoprene of your wetsuit won't compress as
much. And breathing air under less pressure chills you
less.
-
Surface if you shiver. Uncontrollable
shivering is a warning sign of hypothermia.
-
Break the wind. Between dives, a wet
exposure suit becomes a swamp cooler. Many divers
actually lose more heat between dives than when in the
water. Wear a parka or a windbreaker, or take off the
suit and dry off.
10 Ways to Avoid
Nitrogen Narcosis
-
Take a course in deep diving from a
qualified instructor. You'll learn warning signs of
narcosis and skills in coping with it, and you'll gain
confidence. Nitrogen narcosis can build on anxiety.
-
Be rested. Fatigue accentuates nitrogen
narcosis.
-
Be clean and sober. A hangover, even the
effects of over-the-counter drugs, can make narcosis
worse.
-
Exhale thoroughly. You'll expel more
carbon dioxide, which seems to accelerate the onset of
narcosis.
-
Plan your dive, dive your plan. Decide
depth, route, frequency of buddy checks, etc. and stick
to it. Leave as few decisions as possible to be made
"under the influence."
-
Watch yourself. Sure, it's supposed to be
fun, but this much fun?
-
Watch your buddy. Does he seem
uncoordinated? Silly? Acting odd?
-
Don't become fatigued. Don't try to do
too much.
-
Watch your instruments. Believe them.
-
When in doubt, ascend. Often, an ascent
of only 10 or 20 feet will clear your head.
8 Dive Boat Dos and
Don'ts
Space is usually at a
premium on dive boats, so secure your gear as neatly and
compactly as possible.
DO:
-
Be early to board, early to gear up.
Rushing increases anxiety and stress.
-
Remember cash for tips.
-
Secure tanks and weights and all other
gear as instructed by crew.
-
Dress completely at your gear station
except for putting on fins. Walk fins-in-hand to the
exit door.
DON'T:
-
Leave open drinks on the camera table.
-
Dip masks in the camera rinse tank.
-
Forget your C-card.
-
Invade dry areas in a wet exposure suit.
9 Ways to Never Get
Lost
-
Descend feet-first. And try to remain
facing in the same direction, so you can correlate what
you see on the bottom with what you saw at the surface.
-
Stop before you go. When you reach
bottom, stop for a moment. Use your compass to orient
yourself to your map. Look around for landmarks that
will help you identify the scene when you return.
-
Use bottom contours. If you know the
anchor is at 60 feet, you can find it by following the
bottom slope to 60 feet, then following that contour.
-
Plan your route. Like, "Up-current at the
80-foot contour for 1,200 psi, then return to the exit
at the 60-foot contour." Following your nose in a random
pattern is more confusing.
-
Look for landmarks. When crossing a flat
bottom, look for memorable landmarks in sight of one
another: a rock outcrop, a large sponge, a bit of
litter. Make your transit of the bottom a series of
legs, from A to B to C to D, and you can find your way
back.
-
Look behind you. On an out-and-back
route, look back from time to time. You'll be more
likely to recognize the scene on your return. Landmarks
often look different from the other side.
-
Note compass headings. If you need to
make an underwater transit from the descent line or
anchor to the reef or the top of the wall, note the
compass heading and note the scene when you arrive. The
reciprocal course will return you to the anchor.
-
Note the direction of the sun. You can
usually see it from under water. If it's on your left
when outbound, it should be on your right for the
return.
-
Learn the names. When you can identify
the different sponges, corals, etc. along your route,
you are more likely to remember them.
Now you too can dive like a pro! |