C) it displaces a volume of water weighing more than its own weight
What two pieces of equipment do you use to control your buoyancy:
A) BCD, B) Fins
Buoyancy control is one of the most important skills you can master because it allows you to control where you are in the water:
A) true
B) false
A) true
an object will be more buoyant in ____ than it would be in ____ :
A) fresh water, salt water
B) salt water, fresh water
B) salt water, fresh water
When you exhale, your lung volume decreases. This means you have ____ buoyancy:
A) more
B) less
B) less
You usually feel pressure only in body air spaces because:
A) your body is mostly made of incompressible liquid, but air is compressible and changes volume with pressure changes.
B) water is denser than air, which resist pressure better
A) your body is mostly made of incompressible liquid, but air is compressible and changes volume with pressure changes
Pressure changes in water for a given ascent or desent are much more substantial than the same distance ascent or descent in air because water weighs more:
A) true
B) false
A) true
what is the absolute presure in atmospheres or bar for 10 metres/33 feet:
2 bar, 1/2 volume
what is the absolute presure in atmospheres or bar for 20 metres/66 feet:
3 bar, 1/3 volume
what is the absolute presure in atmospheres or bar for 30 metres/99 feet:
4 bar, 1/4 volume
what is the absolute presure in atmospheres or bar for 40 metres/132 feet:
5 bar, 1/5 volume
The three major air spaces affected b pressure when you descend are:
B) mask, ears and sinuses
A squeeze is:
A) a pressure imbalance in which pressure inside an air space exceeds pressure outside an air space, resulting in pain or discomfort.
B) A pressure imbalance in which pressure outside an air space exceeds pressure inside an air space, resulting in pain or discomfort.
B) A pressure imbalance in which pressure outside an air space exceeds pressure inside an air space, resulting in pain or discomfort.
Equalization is adding air to an air space as you descend so the pressure in an air space equals the surrounding water pressure:
A) true
B) false
A) true
Which are techniques for equalizing your ears:
A) pinch your nose and blow gently against it. B) swallow and wiggle your jaw from side to side
You want to equalize your ears:
A) every meter/few feet before you feel discomfort
If you feel discomfort and can't equalize, ascend until you relieve the discomfort and try again. Don't be forceful in equlizing. if you can't equalize, discintinue the dive.
A) true
B) false
A) true
The most important rule in scube diving is, Breathe continuously and never hold your breath:
A) true
B) false
A) true
Ascending while holdiing your breath:
A) can cause lung over expansion injuries
B) can cause serious injuries, including paralysis and death
C) causes injuries that are easy to avoid by not holding your breath
A) can cause lung over expansion injuries
B) can cause serious injuries, including paralysis and death
C) causes injuries that are easy to avoid by not holding your breath
A reverse block is:
A) pain and discomfort caused by expanding air trapped inside an air space during ascent
B) pain and discomfort caused by outside pressure on an air space
A) pain and discomfort caused by expanding air trapped inside an air space during ascent
If you feel discomfort during ascent due to a reveerse block, you should:
A) slow or stop your ascent and give the trapped air time to work its way out
As you go deeper, you consume air from your scuba cylinder:
A) faster
The most efficient method for breathing underwater is rapid and shallow:
A) true
B) false
