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91 Cards in this Set

  • Front
  • Back
Your open water certification means:
Your open water certification qualifies you t dive in conditions similar to those in which you did your open water certification dives.
When is diving particularly strenuous?
When you dive in cold water, strong currents, or make beach entries through surf.
The best way to stay fir for diving is...
to dive regularly or swim with mask, fins and snorkel.
What substances should never be used before diving because they alter your physiology and affect your ability to think clearly?
alcohol, weed, cocaine
If you are ill and do not feel well enough to dive without medication what should you do?
You should not dive because the effects of the drug can be changed by the pressure in unpredictable ways.
The comfort and fit of each item you wear is extremely important because ...
you wear most pieces of dive gear directly on you body.
What's the most important consideration when you select a mask?
Whether the mask fits your face.
What is one essential feature of a mask?
A tempered glass lens to help resist breaking and avoid injury if the lens breaks.
How long should your snorkel be?
30-35 cm [12-14 inches]
What happens if your snorkel is too short?
It will constantly fill with water.
What happens if your snorkel is too long?
It will be harder to get a good breath of fresh air.
What should the inside diameter of the snorkel be?
No less than 2 cm [3/4 of an inch] If it's too small, it's like breathing through a straw. If it's too big, it's awkward to clear.
What must you wear with heal-strap fins to protect your feet from blisters?
Booties

T/WB
What can cause your legs to cramp and will not be comfortable?
Fins that are too large and stiff for your legs muscles.

WB only
RESPONSIBLE DIVING PRACTICE
In some areas of the world you aren't allowed to wear gloves when you dive. This ensures that you will not touch the reef and harm the delicate corals.
Cozumel, Mexico is one example.
Why shouldn't you leave your gear in the sun anymore than necessary?
Sunlight and hear are extremely damaging to scuba gear and neoprene.
What should you do with your gear after every diving day?
Rinse everything with fresh water.
What should you do at the end of your diving trip?
Soak your gear overnight in fresh water then rinse it thoroughly with fresh water.
Where should you store your gear?
A cool dry place like a closet.
What should you do before you store your gear?
Make suer it's dry.
What are most dive cylinders make of?
Dave tanks is another term for cylinder.
Aluminum or Steel
p20
What should you remember about steel cylinders?
They are more resistant to exterior damage than aluminum, but if water gets into the tank it will CORRODE AND FORM RUST inside. This ruins the tank.

WB only p20
What marking is included on the shoulder of each cylinder?
-The serial number of the cylinder, it is unique for each cylinder made by a single manufacturer.


p21
What marking is included on the shoulder of each cylinder?
-The material that the cylinder is made of
-The hydrostatic testing date of the cylinder 8/97 means it was tested in Aug. of 1987

p22
How do you open a valve on a cylinder?
You open the valve by turning a handle/knob counterclockwise and close the valve by turning the knob clockwise, as seen from the top of the valve handle. So when you're looking down at it.

p22 WB only
What is every cylinder valve equipped with?
A pressure relief disk or burst disk.
p23
WB only
How often does a dive cylinder have to be inspected internally and externally?
once per year

p23 T/WB
Who must perform the internal and external inspection?
A certified cylinder inspector

p23 T/WB
Where should you take your cylinder to be internally and externally inspected?
A professional dive shop or dive-equipment repair facility

p23 T/WB
How often, in the US, is hydrostatic testing required?
Every 5 years or whenever the cylinder must be cleaned by tumbling.

p24 T/WB
How should you store a cylinder long term (for a long time)?
with some pressure in the cylinder. In steel tanks, this ensures that water can't enter the cylinder and cause corrosion.
p24
Regulators:
First Stage, what does it do?
The high-pressure air from the cylinder is reduced to approximately 10 bar (150 psi) above the pressure surrounding the cylinder.
p25
Regulators:
Where is your submersible pressure gauge attached.
To a high-pressure port on the FIRST STAGE of your regulator.
p25
Regulators:
What does your submersible pressure gauge monitor?
Your air supply.

p25 WB only
Regulators:
Second Stage, what does it do?
Further resuces the air pressure from approximately 10 bar (150 psi) above the surrounding pressure to whatever the ambient pressure is.
p26
When will you need a high performance regulator?
if you plan on doing deep, wreck, cave. or ice diving, or if you do underwater hunting

p26 WB
What is the most common alternate air source?
An octopus regulator

p26
What is an octopus regulator?
The octopus regulator is an additional second stage that allows you to share air from your cylinder with another diver.
p26
What is another type of alternate air source?
A combination regulator and power-inflator for your buoyancy compensator that fits on its power-inflator hose.
p27
What does contingency scuba provide?
An excellent backup for ourself if you and your buddy get separated under water.

p27 WB
What do gauge and instruments tell a diver?
depth, bottom time, direction, and air supply (how much air you have in the cylinder at any given time)
p27
What is a dive console and what does it do?
It puts all your gauges in one handy unit. It streamlines your gauges into one unit.
p27 WB
Is a submersible pressure gauge (SPG) a required piece of equipment for scuba diving?
YES

p28
What does a depth gauge do?
Monitors your depth when you dive.
p28
Why do you monitor your depth when you dive?
Your depth and the duration of your dive at any particular depth are limited by a number of factors, so you need to know and monitor your depth.
p28
Why is a depth gauge that uses a capillary tube very useful at depths above 12 meters/40 ft. but not recommended for deeper depths?
The scale size becomes too small for accurate readings.

p29 WB
What must a diving compass have?
A diving compass must have a reference line, called a lubber line, used as the direction of travel.
p30
What should you do when your regulator is off the cylinder?
You should replace the dust cap that fits over the inlet to the first stage whenever your regulator is off a cylinder.
p30
Never press the purge button when running water through the mouth piece of your regulator.
Just know this.

p30 WB
How often must you have your regulator serviced by a certified repair technician?
At least once a year.

p30
What two things must you keep track of when you dive?
Your depth and time you stay under water.

p31
A rotating bezel around the dial of the watch or a stopwatch feature will measure elapsed dive time.
Know this for WB.

WB 31
At a minimum, what 4 things should a dive computer record or display?
maximum depth
current depth
actual dive time
remaining allowable dive time
p32
Buoyancy Compensator [BC]
What must a BC be equipped with?
-an overpressure relief valve
-inflator/deflator hose that is at least 2 cm. in diameter
-power-inflator mechanism and deflator/oral inflator valve at the end of the inflator/deflator hose
p33
Why do you wear a weight belt when you dive?
You wear a weight belt to offset the buoyancy of your body, your wetsuit, ad other diving gear you are wearing.
p36
What must the weight system you choose have?
All weight systems must have a quick release that enables you to ditch your weights with one hand.
p37
What is a contributing factor in many diving accidents?
cold water
p37
Why is it essential to wear the tight thermal protection for the conditions where you dive?
When you get cold underwater you lose your ability to perform at your best. Heat loss under water affects your ability to think and you fatigue rapidly.
p37
What are dive knives used for?
they are working tools used for may purposes. It's most important function might be to cut fishing line or nets if you get tangled in them under water. They are not to fight sharks as you may have seen on TV.
p42
How should you select a dive knife?
Select a dive knife that is the most appropriate for the diving you do. An underwater hunter might want a thin sharp blade while a wreck diver might want a knife with a heavy blunt tip for prying and pounding.
p43
What is the key to a successful surface dive?
The key to a successful surface dive is to get as much of your body our of the water as possible.
p52
You must know how your buddy's equipment works and they must know how to operate yours in case of an emergency.
Just know this.

p61
What general rule applies to most boat and platform entries?
You should make sure that the entry area below you is clear and sufficiently deep for the type of entry you are using.
p62
How do you check your buoyancy at the surface?
Take in a deep breath and hold it while you hang in the water motionless. If you re properly weighted, you will float at eye level.
p73
When descending, exhale and begin your feet-first decent. Remember to breath out completely and then take in a small breath of air.
Just know this.
p73
What happens when you are wearing a wetsuit and make descents in open water?
You will lose buoyancy as the pressure of the water compresses you wetsuit. You need to add small amounts of air to your BC to compensate for the compression of the wetsuit.
p74
What is the maximum speed of ascent?
Your rate of ascent must not exceed a speed of 9 meters/30 feet per minute if you are using dive tables.
p75
What are the benefits of descending feet-first?
Descending feet first gives you better control of your speed, buoyancy, and ability to clear your ears.
p74
Emergency Swimming Ascent

You do this when you run out of air at shallower depths. [18 meters/60 ft.] It can be done at deeper depths, but having contingency air supply is superior and recommended for deeper dives.
-look up to maintain an open airway
-swim to the surface while exhaling a continuous stream of bubbles from your regulator
-keep the regulator in your mouth during an emergency ascent, as the water pressure decrease, you will get another small breath of air from your cylinder.
-be ready to vent air from your BC to control your buoyancy during the ascent
p79
Surface Communication
You will use different types of audible and visual signals to communicate.
You use some of the standard hand signals at the surface. If you wave to someone from the surface, it is a sign of distress, NOT a way to say hello.
p84
In what direction do ripple marks on the bottom form.
Ripple marks in the sand on the bottom form parallel to the shore.
p87
What are some examples of underwater landmarks?
These help you navigate and keep track of your position under water.
rock formations
large and unique plants
crevices
wrecks
p88
Air has weight.
One liter of air weighs 1.25 grams In the Imperial System it's .08 pounds per cubic foot
p84
Water has weight.
1L of fresh water weighs 1.0 kilograms; 1L of salt water is 1.025 kg. Imperial system uses cubic feet. 1 cubic foot of water weighs 62.4 lbs; 64 lbs. per cubic foot of salt water
What effect does refraction have on object under water?
Refraction (the bending and slowing of light rays) makes objects appear 1/3 closer and larger than they do in air. So things are smaller and farther away than they look under water.
Colors look different underwater.
As light passes through water, the water absorbs the colors of the spectrum. What order does this happen in?
Red is the first visible color to be absorbed, then orange, yellow, green, blue, indigo and finally violet. p95
Why do sound waves travel faster in water than in air?
Water has a greater density so sound travels about four times faster in water than in air. It's hard to tell the source of sound underwater. p96
Water is denser than air and can conduct a great deal of heat without changing temperature. What does this have to do with diving.
Heat can be conducted out of your body by direct contact with water nearly 25 times faster than by air.
p97 Equipment
Just know this.
Water resists your movement, this is called drag.
p97
If your equipment is sleek and compact it will be easier for you to swim than if you have gear dangling off you. The more streamline you are, the less drag you will experience.
Buoyancy p98

Positive buoyancy, an object with positive buoyancy floats.
Why?
The object displaces a amount of water that weighs more than the object does. In other words the object is less dense than the water. You want to float when you are at the surface before and after you dive.
p99
Bubbles in your wetsuit compress as you go deeper so the wetsuit displaces less water and looses buoyancy. What do you have to do to How do you compensate for this?
To compensate for loss of buoyancy you must add air to your BC. This increases your volume to regain the lost buoyancy.
p101
What does the term "bar" refer to?
Pressure is measured in bars. A bar is measured in pounds per square inch. (psi)
p101
Water exerts pressure on you as you descend.
Just know this.
10.3 meters/34 feet of fresh water is equivalent of 1 atmosphere of pressure.
pg. 102
Just know this. Water is not compressible and transmits pressure freely.
Pressure in water increases at a constant rate and pressure is cumulative.
In other words, 10 meters, (33 feet) of salt water equals 1 atmosphere; 20 meters (66 feet) of salt water equals 2 atmosphere; 30 meters )99 feet) of salt water equals 3 atmosphere
pg. 102
What is the difference between absolute pressure (ata) and gauge pressure
Absolute pressure is the pressure of the water above you plus the pressure of the air above the water. At sea level it's water pressure plus 1 atmosphere. Gauge pressure is only the pressure of the water above you. Most diving depth gauges (pressure gauges) are calibrated or adjusted to read zero at sea level.
pg. 103
There is an inverse relationship between pressure and volume. This is known as Boyle's Law
As pressure on air increases, the volume decreases. At 10 meters/33 feet of sea water or 2 ata, the pressure has doubled and the volume of a given amount of air has decreased to half of the original surface volume.
pg. 105
How does pressure affect air consumption?
The rate at which you consume the air in your cylinder is directly proportional to the depth of your dive. You consume twice the air at 10 meters/33 feet as you do on the surface three times at 20m/66ft. and so on
pg.105
What other factors affect the rate at which you consume air on your dive?
Your activity level during the dive. Your mental state. Your body size. Your level of physical fitness.
pg. 105 [book only]
Besides depth, what has the greatest effect on you r air consumption under water?
Physical Activity under water. You can use up to four times as much air when you are exerting yourself than when resting.
pg.105
As a diver, what breathing pattern should you think about developing under water?
You should develop a slow and relaxed breathing pattern as well as a slow rate of breathing. When you swim fast under water, you breathe more deeply and ore often.
pg. 106
How does physical size affect air consumption?
Larger people have larger lungs and use more air than smaller people who have smaller lungs and smaller overall metabolic needs.
pg. 107
How do you equalize your middle ear and avoid ear squeeze?
You equalize your middle ear by moving air from your throat through the Eustachian tube into your middle ear.