PADI Open Water DIve Course Summary

0m/0ft = ? (pressure)

1 bar/ata

Pressure at sea level

1 bar/ata(atmosphere)

10m/33ft = ? (pressure)

2 bar/ata

20m/66ft = ? (pressure)

3 bar/ata

30m/99ft = ? (pressure)

4 bar/ata

40m/132ft = ? (pressure)

5 bar/ata

Ex. Suppose you fill a balloon completely and seal it at 10 metres/33 feet. What happens as you ascend?

The balloon expands, growing larger until it stretches past its failure point and bursts. To prevent this, you'd leave the balloon unsealed and vent some of the expanding air as you ascend.

three types of buoyancy

positive, negative, neutral

Overall benefits of the buddy system include (choose all that apply): a. safety b. fun c. practicality

All of the above

Which of the following are among the breathing rules I follow as a diver? (choose all that apply): a. If faced with a problem, stop, then maintain or restore slow, deep breathing. b. Breathe continuously and never, ever, hold my breath. c. Breathe slowly and deeply. d. Do not allow myself to get winded or out-of-breath.

All of the above

Positive Bouyancy

If an object weighs less than the water it displaces, it floats

negative buoyancy

If an object weighs more than the water it displaces, it sinks

neutral buoyancy

If an object weighs the same as the water it displaces, it neither floats nor sinks

As I descend, increasing pressure affects my (choose all that apply): a. mask b. ears c. skin d. sinuses

Mask, ears, sinuses

What is a "squeeze"?

The discomfort caused by pressure imbalance pulling tissue into the air space

Ex. Suppose you have 1 litre of air at 30 metres/99 feet. What would the volume and density be at the surface?

Volume = 4 litre Desnity = 1/4

reverse block (reverse "squeeze")

a condition that occurs when expanding air cannot escape from a body air space during ascent, causing pain ad comfort

A depth change of 10 metres/33 feet causes a pressure change of a. 1 bar/ata. b. 2 bar/ata. c. 3 bar/ata. d. 4 bar/ata.

a. 1 bar/ata.

Buoyancy is a force that pushes an object in water upward. a. True b. False

a. True

Failure to follow the most important rule in scuba diving can cause severe lung overexpansion injuries, which can result in paralysis or death. a. True b. False

a. True

Getting the service my gear needs may be a consideration when choosing equipment. a. True b. False

a. True

I equalize gently because an extended, forceful equalization can cause permanent damage to my ears and hearing. a. True b. False

a. True

In recreational diving, the buddy system means diving with another diver or divers in a team that provides assistance and safety benefits. a. True b. False

a. True

It is important to master buoyancy control because it affects almost everything I do in and underwater. a. True b. False

a. True

My body responds to anxiety with increased breathing, but slow breathing helps reduce anxiety. a. True b. False

a. True

When scuba diving, normal breathing keeps your lungs equalized to the surrounding pressure. a. True b. False

a. True

A squeeze is caused by a. a pressure imbalance between the surrounding pressure and an air space. b. wearing my wet suit or other gear too tightly.

a. a pressure imbalance between the surrounding pressure and an air space.

Equalization is the process of a. adding air to an air space. b. removing air from an air space. c. reducing the surrounding pressure. d. increasing the surrounding pressure.

a. adding air to an air space.

When I descend, my buoyancy tends to _________. When I ascend, it tends to __________. a. decrease, increase b. increase, decrease c. increase, increase d. decrease, decrease

a. decrease, increase

The most efficient way to breathe dense air underwater is to breathe a. deeply and slowly. b. shallowly and rapidly. c. shallowly and slowly. d. deeply and rapidly.

a. deeply and slowly.

Underwater, when I inhale, my buoyancy a. increases slightly. b. doesn't change. c. decreases slightly.

a. increases slightly.

Before each use, I should__________________my equipment. a. inspect b. wash c. warm d. dry

a. inspect

If you take 6 litres of air from the surface to 20 metres/66 feet, the volume will be _____ litres. a. 1 b. 2 c. 3 d. 4

b. 2

Salt water causes more buoyancy than fresh water because it is less dense and weighs less. a. True b. False

b. False

The most important rule in scuba diving is to a. check your air supply every five minutes. b. breathe continuously and never hold your breath. c. always dive with a buddy

b. breathe continuously and never hold your breath.

A balloon fully inflated and sealed at 10 metres/33 feet, would probably _______ during ascent to the surface. a. shrink (become smaller) b. burst

b. burst

The three most important considerations in choosing scuba equipmentare suitability, fit and ____________. a. color and style b. comfort c. dcost and features . manufacturer

b. comfort

I'm descending and discover I can't equalize. The first thing I would do is a. equalize more forcefully. b. stop my descent and signal my buddy/the instructor. c. slow my descent and see if the problem corrects itself.

b. stop my descent and signal my buddy/the instructor.

During ascent I feel discomfort in my ears. I should a. continue my ascent at a slightly faster rate. b. stop, descend slightly and allow trapped air to work its way out. c. use a decongestant before my next dive. d. equalize by blowing gently against blocked nostrils.

b. stop, descend slightly and allow trapped air to work its way out.

To control my buoyancy, normally I will use my weight system and my a. scuba cylinder. b. fins. c. BCD. d. wet suit.

c. BCD.

I should equalize a. when I feel pain or discomfort. b. only if I can't tolerate the pain or discomfort. c. before I feel pain or discomfort. d. when I reach the bottom.

c. before I feel pain or discomfort.

On a day I plan to go diving, I wake up with my sinuses blocked due to a cold or allergy. I should a. take an approved decongestant so I will be able to equalize. b. plan to take a lot longer as I descend. c. cancel the dive until I'm well.

c. cancel the dive until I'm well.

My buddy and I descend to 12 metres/40 feet. I would expect to use my air __________ at 6 metres/20 feet. a. at the same rate as b. slower than c. faster than

c. faster than

As you descend in water the pressure a. decreases. b. does not change. c. increases.

c. increases.

My sunglasses case falls out of my pocket into the water, but fortunately, it floats so I retrieve it. I would say my sunglasses case is _______ buoyant. a. neutrally b. negatively c. positively

c. positively

The density of the air in the previous question would be ________ the density at the surface. a. one-third b. one-half c. three times d. four times

c. three times