Open water diving Essay

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Pages: 11

Name __________________________________________________________ Date __________________

Open Water Diver Course

Knowledge Review – 1

ANSWER KEY
Answer the following questions and bring this completed Knowledge Review with you to your next training session.
1. True or False. An object is neutrally buoyant when it displaces an amount of water less than its own weight.

False
2. Explain why buoyancy control, both on the surface and underwater, is one of the most important skills you can master. To conserve energy while resting or swimming.
To stay off the bottom and avoid crushing or damaging delicate aquatic life.

On the surface:
Underwater:

3. Fill in the blanks with the appropriate words: fresh water or salt water.
“The same object would be more buoyant in

salt water than it would be in fresh water.”

4. True or False. “Because water is much denser than air, the pressure change for a given distance ascent or descent is significantly greater in water than in air.’’

True
5. Complete the following chart for a sealed flexible bag, full of air at the surface.
Depth

Pressure

Volume

Density

0'

1 bar/ATM

1

x1

10m/33'

2 bar/ATM

1/2

x2

30m/99'

4 bar/ATM

1/4

x4

40m/132'

5 bar/ATM

1/5

x5

6. Circle the letter of the best definition for a squeeze.
a. A condition that causes pain and discomfort when the pressure outside an air space of your body is less than the pressure inside an air space.
b. A condition that causes pain and discomfort when the pressure inside an air space of your body is less than the pressure outside an air space.

495DT Ver 1.0 (Rev 10/10)

PADI © 2010

7. Check each statement that describes a technique used to equalize air spaces during descent:





a. Block your nose and attempt to gently blow through it.
b. Swallow and wiggle the jaw from side to side.
c. Block your nose and attempt to gently blow through it while swallowing and wiggling the jaw from side to side.

8. State how often you should equalize your air spaces during descent.

Every few metre/feet, before discomfort is felt.
9. True or False. “If you feel discomfort in your ears while descending, continue downward until the discomfort is gone.”

False
10. State the most important rule in scuba diving.

Breathe continuously and never, never hold your breath.
11. Circle the letter of the best definition for a reverse block.
a. A condition that occurs when expanding air cannot escape from a body air space during ascent, causing pain and discomfort.
b. A condition that occurs when expanding air escapes from a body air space during ascent, causing pain and discomfort.

12. Describe what action you should take if you feel discomfort during ascent due to air expansion, whether in your ears, sinuses, stomach, intestines or teeth.

Slow or stop ascent, descend a metre/few feet and allow trapped air to work its way out.
13. When scuba diving, why must your nose be enclosed in the mask?

To exhale into it and equalize.
14. Explain the best way to prevent water from entering your scuba tank.

Never allow a tank to be completely emptied of air pressure.
15. Circle the appropriate answer. The most important feature for consideration when selecting a regulator is:
a. The color

b. The number of hoses it has

c. Ease of breathing

d. Size

Name __________________________________________________________ Date __________________

Open Water Diver Course

Knowledge Review – 2

ANSWER KEY
Answer the following questions and bring this completed Knowledge Review with you to your next training session.

1. Check one. “Underwater, objects appear 33 percent __________ and/or __________.”

 a.

smaller, further away

 b.

larger, closer

2. Check one. Since it travels about four times faster in water than in air, you will have difficulty determining the origin of __________ underwater.

 a.

light

…