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100 Cards in this Set

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  • Back

Positive buoyancy

An object weighs less than the water it displaces

Which two of equipment do you use to control your buoyancy ?

BCD and weights.

Why control your buoyancy one of the key skills?

Because you have this influence on where you are in the water.

What is the difference in buoyancy between fresh and salt water?

An object has more buoyant in salt water than in fresh water. (salt water weighs more by dissolved salt)

How does your breathing affect your buoyancy ?

When you exhale, lung volume decreases. This gives you less buoyant.

Why do you feel changing pressure usually only in the air spaces of your body?

Because your body is composed mainly of non- compressible fluids, but air or compressible and volume changes when the pressure changes.

Why are changes in water pressure greater than in air?

Because water weighs more ( is denser and heavier).

What is the absolute pressure , volume and density at 10m/33ft, 20m/66m, 30m/99ft and 40m/132ft meters ?

2 bar/ata, 1/2, x2
3 bar/ata, 1/3, x3
4 bar/ata, 1/4, x4
5 bar/ata, 1/5, x5

What are the three main air spaces that are affected by the pressure during descent ?

Mask , ears and sinuses .

What is a squeeze ?

A differential pressure at which the pressure in an air space is less than the ambient pressure , with pain or discomfort as a result.

What is clear ?

During the descent, to add air to the air -containing cavities in order to ensure that the pressure in the cavity is equal to the ambient pressure.

What techniques are there to get your ears?

You noses and gently try to exhale, swallowing and your jaw move back and forth , these two things at once.

When should you equalize your ears?

Each meter before it is unpleasant.

What should you do if you feel uncomfortable and can not get equalized ?

Ascend to a higher altitude and try again to finish equalizing . Then descend slowly. End the dive if you can not get equalize .

What is the most important rule when diving?

By continuing to breathe and never hold your breath .

What can happen if you hold your breath when ascending?

This can cause lung over expansion injuries , allowing air into your bloodstream may get into the chest (cause serious injuries including paralysis and death = injuries that easily avoided by not hold your breath )

What is a reverse block ?

Pain or discomfort because of trapped air that expands during ascent .

What should you do when a reverse block ?

Delay or interrupt your ascent and give the trapped air a chance to escape.

What impact has greater depth on how long you do with your air?

As you delve deeper , the air in your tank run out quickly .

What is the most efficient way to breathe underwater ?

Deeply and slowly .

Why do you need a mask underwater to see?

Because the human eye can not focus under water.

Why does your nose need to be inside the mask?

To equalize or clear your mask.

What are the characteristics you seek out a mask?

Small volume, cutout for nose or forthe fingers, large field of view .

What is the most important consideration when buying diving equipment including a mask?

Fit and comfort.

What should you do if you get a new mask for the first time?

Removing the factory applied coating , adjusting the mask strap .

How to maintain your mask?

After use , rinse with tap water , stored in cool, dry space.

Why do you need a snorkel when diving?

To conserve compressed air as you swim to the surface to breathe easier with waves on the surface, if you with an empty bottle travels a greater distance

What characteristics does a snorkel with low breathing resistancehave ?

A larger diameter and uniform , gentle curve .

When a snorkel properly adjusted ?

If he stays in a relaxed jaw in your mouth and is located on the left side of your mask.

Why can move effectively with fins ?

They have a large surface area, so you can use your leg muscles to move through the water. This is much more effective than your arms.

What type of fin you usually use with neoprene booties ?

Adjustable fins .

What characteristics of a fin are designed to improve the performance?

Holes , grooves and ribs ( no wings ) .

What should you do if you use your fins for the first time ?

Nothing special, except the strap adjustment at an open heel fin .

What considerations when buying fins ?

Your body size , your muscle strength and the environment you want to go swimming .

Why do you need a BCD ?

You regulate buoyancy water and above water to have positive buoyancy .

What are the five essential characteristics of a BCD ?

Large diameter hose for venting and filling, lagedrukinflator , pressure relief valve , large enough for sufficient buoyancy , comfortable harness and backpack. H

How to maintain your BCD ?

Rinse (inside and outside) , dry and store in the sun with some air in it (so that the bladder is not sticking to the inside).

Of which two types of metal tanks are usually made ​​of?

Aluminum & steel

What marks are there in a bottle?

Date of hydrostatic test pressure , serial number.

What is the difference between a collar and a J K faucet?

J crane has a spare and a K crane not .

What is the difference between a DIN valve and an yoke?

With a DIN valve is the regulator screwed into the valve and an international crane goes over a bracket . With a DIN valve is the o-ring on the machine and in the yoke on the crane.

Which has a knock ?

This allows air to escape when the filling pressure is too high or the bottle to overheat.

What should you do if you transported tanks ?

She lay down and fix ( sometimes they remain ) so they can not roll , they never leave unattended .

How do you avoid getting water in your tank ?

Never by the bottle completely deflate to empty.

Why is a yearly visual inspection of your tank need?

To check for corrosion within the cylinder .

How many steps does the machine lowers the pressure of the air in the bottle?


What is the second step ?

Mouthpiece and therearound.

Where you need to when rinsing your machine think ?

That you reinstall the dust cover of the 1st stage , not the purge button, use a soft beam .

What's a gauge?

Required component that tells you how much air you have left .

What are the reasons to dive with a buddy ?

Practical considerations , safety , fun.

How does the water affect he way you see/perceive things?

You see everything larger and / or closer.

How influenced water the intensity of color and light?

Water absorbs light, making it darker as you go deeper and colors are less intense.

How does sound under water?

Sound travels 4x faster under water , making it difficult to determine where it comes from . Sounds usually seem to come from above.

How fast water absorbs heat ?

20 times faster than air.

What should you do if you begin shivering continuously ?

Immediately terminate your dive, afdroken yourself and enjoy the warmth .

What is the most efficient way to move underwater ?

Slow, steady and relaxed.

How to breathe underwater for max efficiency ?

Slowly and deeply.

What are eight symptoms of overexertion ?

Fatigue, breathing heavily , the feeling that you choke , weakness , shortness of breath , headache, cramps, tend to panic.

How can you prevent overexertion ?

Take it easy , knowing your own limits , avoid prolonged exertion.

What should you do if you get overtired ?

Stop any form of exercise tasks and rest.

What are techniques to keep your breathing under control?

Slowly breathe when water enters your machine or snorkel , gently inhale as you've just done , use your tongue as a splash guard .

What information will be shown on your dive computer?

Time, depth , direction, temperature and air supply .

Why do you need a gauge ?

Because the time limits depth bound .

Why do you need an underwater compass ?

To determine where you can leave the water and follow a course.

What are nine things you should discuss with your buddy when planning a dive ?

Agree on where your water comes in and out , and what techniques you typically used for this purpose. Determine which direction you are going to follow , make agreements on time and depth limits , take the communication , meet at any cylinder pressure you return , discuss how to stay together, what you do when you lose each other , emergency procedures , what the purpose of the dive .

What's the predive safety check?

(BWRAF) Bruce Willis Ruins All Films

BCD - Weights - Releases - Air - Fins

Which six environmental factors may affect you in any water environment?

Temperature, visibility, water movement, soil , water and sunlight life .

What's a thermocline?

An abrupt transition to a low cooler water.

What four factors influence the sight?

Weather, water movement , particulate matter and soil conditions.

Why is also in clear water recommended to use a rope to ascend and descend and a depth gauge?

The soil may appear closer than it is and you can become disoriented .

What causes currents?

The wind that blows across the surface , uneven uneven heating and cooling of the water , tides and currents (waves ..? ) ...

What are considerations for diving in fresh water?

Deep water , height, termoclines and limited visibility.

Opverwegingen for salt water.

Surf , tide , sea life , waves.

What causes waves and how do you avoid that ?

As the wind blows over the surface and produces waves , you avoid by diving deeper.

Indicate where waves break on the coast ?

An offshore lying reef , wreck or sandbar ( shoal on which waves break )

What's a rip current?

A rip current occurs when waves push water over a long obstruction as a sandbar or reef. The water can on the underside does not matter, so the steam back into the sea through a narrow opening. You can recognize a rip current to disruption of the waves, strong currents and murky landafwaardse sudsy water .

If you end up in a rip current, what should I do to get out of it?

Swim parallel to the coast.

What's an upwelling?

A slow flow that occurs when the surface area of ​​about water through a land breeze is pushed away from the coast . There will then deep water upwards to compensate for the loss .

At which the tide diving conditions are usually the best?

Rampant? wth

Which four steps are involved in a dive plan?

Advance planning, preparation planing, last minute preparation and predive planning.

5 steps which follow during the pre-planning ?

buddy dive purpose , dive site, alternative place , time

Preparation planning steps:

Check your equipment and conditions

What do you do at the last-minute preparation ?

check weather , info show back home , things last address as cooler and jacket, bag and idiot stuff in check.

How can you avoid most of the problems on the surface ?

By diving within your limits , during a dive to relax and to provide positive buoyancy .

How can you avoid most problems under water?

By diving within your limits , your air supply to keep watch and relax.

What problems can occur under water?

overexertion , without air get trapped , lifts off, automatic, entanglement.

What is the procedure if I find I have little or no air ?

Normal ascent, ascend with alternate air source, controlled emergency swimming ascent (CESA) , buoyant emergency ascent.

How far have you and your dive flag boats keep coming from?

You should be within 50ft. Boats should stay at least 100-200ft away.

What are the two gases, which consists mainly of air ?

Oxygen, 21% nitrogen and 79%.

What are five possible symptoms of polluted air ?

headache , nausea, cherry red lips and toenails, dizziness , fainting.

What should you do if a diver breathes polluted air has been ?

The diver with fresh air , pure oxygen and if present consult doctor.

How do you prevent problems with contaminated air ?

How do you prevent problems with Only fill at reputable sources.

How do you prevent problems with oxygen?

Never let your bottle filled with pure oxygen , no nitrox use without training , diving within the limits of recreational diving.

What are the symptoms of nitrogen narcosis ?

Strange behavior , false sense of security unrest.

Probably something about how do you treat nitrogen narcosis?

Ascend to a shallow depth.

How can you avoid nitrogen narcosis ?

Never dive deeper than 60 ft

What affects nitrogen in your body?

Depth and time.

What is decompression sickness?

The state ontstaant when a diver the prescribed time and depth limits overschreid and bubbles form in the body.

What are signs of decompression sickness?

paralysis , shock, weakness, dizziness , numbness, tingling, trouble breathing , pain in limbs and joints.

Negative buoyancy

object weighs more than the water it displaces