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100 Cards in this Set
- Front
- Back
Positive buoyancy |
An object weighs less than the water it displaces |
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Which two of equipment do you use to control your buoyancy ? |
BCD and weights. |
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Why control your buoyancy one of the key skills? |
Because you have this influence on where you are in the water. |
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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) |
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How does your breathing affect your buoyancy ? |
When you exhale, lung volume decreases. This gives you less buoyant. |
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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. |
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Why are changes in water pressure greater than in air? |
Because water weighs more ( is denser and heavier). |
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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 |
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What are the three main air spaces that are affected by the pressure during descent ? |
Mask , ears and sinuses . |
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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. |
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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. |
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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. |
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When should you equalize your ears? |
Each meter before it is unpleasant. |
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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 . |
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What is the most important rule when diving? |
By continuing to breathe and never hold your breath . |
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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 ) |
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What is a reverse block ? |
Pain or discomfort because of trapped air that expands during ascent . |
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What should you do when a reverse block ? |
Delay or interrupt your ascent and give the trapped air a chance to escape. |
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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 . |
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What is the most efficient way to breathe underwater ? |
Deeply and slowly . |
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Why do you need a mask underwater to see? |
Because the human eye can not focus under water. |
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Why does your nose need to be inside the mask? |
To equalize or clear your mask. |
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What are the characteristics you seek out a mask? |
Small volume, cutout for nose or forthe fingers, large field of view . |
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What is the most important consideration when buying diving equipment including a mask? |
Fit and comfort. |
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What should you do if you get a new mask for the first time? |
Removing the factory applied coating , adjusting the mask strap . |
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How to maintain your mask? |
After use , rinse with tap water , stored in cool, dry space. |
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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 |
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What characteristics does a snorkel with low breathing resistancehave ? |
A larger diameter and uniform , gentle curve . |
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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. |
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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. |
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What type of fin you usually use with neoprene booties ? |
Adjustable fins . |
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What characteristics of a fin are designed to improve the performance? |
Holes , grooves and ribs ( no wings ) . |
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What should you do if you use your fins for the first time ? |
Nothing special, except the strap adjustment at an open heel fin . |
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What considerations when buying fins ? |
Your body size , your muscle strength and the environment you want to go swimming . |
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Why do you need a BCD ? |
You regulate buoyancy water and above water to have positive buoyancy . |
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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 |
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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). |
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Of which two types of metal tanks are usually made of? |
Aluminum & steel |
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What marks are there in a bottle? |
Date of hydrostatic test pressure , serial number. |
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What is the difference between a collar and a J K faucet? |
J crane has a spare and a K crane not . |
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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. |
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Which has a knock ? |
This allows air to escape when the filling pressure is too high or the bottle to overheat. |
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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 . |
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How do you avoid getting water in your tank ? |
Never by the bottle completely deflate to empty. |
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Why is a yearly visual inspection of your tank need? |
To check for corrosion within the cylinder . |
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How many steps does the machine lowers the pressure of the air in the bottle? |
Two |
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What is the second step ? |
Mouthpiece and therearound. |
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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 . |
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What's a gauge? |
Required component that tells you how much air you have left . |
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What are the reasons to dive with a buddy ? |
Practical considerations , safety , fun. |
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How does the water affect he way you see/perceive things? |
You see everything larger and / or closer. |
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How influenced water the intensity of color and light? |
Water absorbs light, making it darker as you go deeper and colors are less intense. |
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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. |
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How fast water absorbs heat ? |
20 times faster than air. |
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What should you do if you begin shivering continuously ? |
Immediately terminate your dive, afdroken yourself and enjoy the warmth . |
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What is the most efficient way to move underwater ? |
Slow, steady and relaxed. |
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How to breathe underwater for max efficiency ? |
Slowly and deeply. |
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What are eight symptoms of overexertion ? |
Fatigue, breathing heavily , the feeling that you choke , weakness , shortness of breath , headache, cramps, tend to panic. |
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How can you prevent overexertion ? |
Take it easy , knowing your own limits , avoid prolonged exertion. |
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What should you do if you get overtired ? |
Stop any form of exercise tasks and rest. |
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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 . |
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What information will be shown on your dive computer? |
Time, depth , direction, temperature and air supply . |
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Why do you need a gauge ? |
Because the time limits depth bound . |
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Why do you need an underwater compass ? |
To determine where you can leave the water and follow a course. |
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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 . |
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What's the predive safety check? |
(BWRAF) Bruce Willis Ruins All Films
BCD - Weights - Releases - Air - Fins |
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Which six environmental factors may affect you in any water environment? |
Temperature, visibility, water movement, soil , water and sunlight life . |
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What's a thermocline? |
An abrupt transition to a low cooler water. |
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What four factors influence the sight? |
Weather, water movement , particulate matter and soil conditions. |
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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 . |
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What causes currents? |
The wind that blows across the surface , uneven uneven heating and cooling of the water , tides and currents (waves ..? ) ... |
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What are considerations for diving in fresh water? |
Deep water , height, termoclines and limited visibility. |
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Opverwegingen for salt water. |
Surf , tide , sea life , waves. |
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What causes waves and how do you avoid that ? |
As the wind blows over the surface and produces waves , you avoid by diving deeper. |
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Indicate where waves break on the coast ? |
An offshore lying reef , wreck or sandbar ( shoal on which waves break ) |
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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 . |
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If you end up in a rip current, what should I do to get out of it? |
Swim parallel to the coast. |
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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 . |
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At which the tide diving conditions are usually the best? |
Rampant? wth |
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Which four steps are involved in a dive plan? |
Advance planning, preparation planing, last minute preparation and predive planning. |
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5 steps which follow during the pre-planning ? |
buddy dive purpose , dive site, alternative place , time |
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Preparation planning steps: |
Check your equipment and conditions |
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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. |
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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 . |
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How can you avoid most problems under water? |
By diving within your limits , your air supply to keep watch and relax. |
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What problems can occur under water? |
overexertion , without air get trapped , lifts off, automatic, entanglement. |
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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.
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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. |
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What are the two gases, which consists mainly of air ? |
Oxygen, 21% nitrogen and 79%. |
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What are five possible symptoms of polluted air ? |
headache , nausea, cherry red lips and toenails, dizziness , fainting. |
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What should you do if a diver breathes polluted air has been ? |
The diver with fresh air , pure oxygen and if present consult doctor. |
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How do you prevent problems with contaminated air ? |
How do you prevent problems with Only fill at reputable sources. |
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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. |
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What are the symptoms of nitrogen narcosis ? |
Strange behavior , false sense of security unrest. |
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Probably something about how do you treat nitrogen narcosis? |
Ascend to a shallow depth. |
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How can you avoid nitrogen narcosis ? |
Never dive deeper than 60 ft |
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What affects nitrogen in your body? |
Depth and time. |
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What is decompression sickness? |
The state ontstaant when a diver the prescribed time and depth limits overschreid and bubbles form in the body. |
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What are signs of decompression sickness? |
paralysis , shock, weakness, dizziness , numbness, tingling, trouble breathing , pain in limbs and joints. |
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Negative buoyancy |
object weighs more than the water it displaces |