PADI Open Water Certification Study Guide
1. When is an object positively buoyant? When it displaces a volume of water
weighing more than its own weight.
2. When is an object negatively buoyant? When it displaces a volume of water
weighing less than its own weight.
3. When is an object neutrally buoyant? When it displaces a volume of water
weighing the same as its own weight.
4. Why two pieces of equipment do you BCD, Lead weight
use to control your buoyancy?
5. What does buoyancy help with when
Controlling where you are
you are underwater?
6. What does buoyancy help with when
Floatation, conserving energy
you are at the surface?
7. How does the buoyancy of an object
differ in fresh/salt water? More buoyant in salt than fresh
8. When you exhale what happens? Lung volume decreases so you have
less
buoyancy.
9. When you inhale what happens? Lung volume increases so you have
more
buoyancy.
10. Why don't you feel air pressure? Your body is primarily liquid, which is
incompressible and distribute
pressure equally throughout your
whole body.
11. Where are some air spaces located in the body?
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, PADI Open Water Certification Study Guide
Ears, sinuses, lungs
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, PADI Open Water Certification Study Guide
12. Do you always feel the pressure in body air Only if the pressure is ditterent
inside and
spaces? outside the air spaces.
13. 1 bar is what depth? 0m/0ft
14. 2 bar is what depth? 33ft/10m
15. 3 bar is what depth? 66ft/20m
16. 4 bar is what depth? 99ft/30m
17. How is air volume affected when It decreases
depth is increased?
18. How is air density affected when
It increases
depth is increased?
19. What happens if you take an air
volume As pressure increases the volume
decreas-
underwater with you in a flexible container es, same air but smaller
space.
or inverted jar?
20. How do you maintain air volume as Equalize
you descend?
21. What is a "squeeze"? As volume decreases, pressure
pushes body tissues inwards
toward air space, causing
discomfort. Pressure outside air
space is more than pressure
inside air space.
22. Where can you get a squeeze? Ears, sinuses, mask, lungs, teeth
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22
1. When is an object positively buoyant? When it displaces a volume of water
weighing more than its own weight.
2. When is an object negatively buoyant? When it displaces a volume of water
weighing less than its own weight.
3. When is an object neutrally buoyant? When it displaces a volume of water
weighing the same as its own weight.
4. Why two pieces of equipment do you BCD, Lead weight
use to control your buoyancy?
5. What does buoyancy help with when
Controlling where you are
you are underwater?
6. What does buoyancy help with when
Floatation, conserving energy
you are at the surface?
7. How does the buoyancy of an object
differ in fresh/salt water? More buoyant in salt than fresh
8. When you exhale what happens? Lung volume decreases so you have
less
buoyancy.
9. When you inhale what happens? Lung volume increases so you have
more
buoyancy.
10. Why don't you feel air pressure? Your body is primarily liquid, which is
incompressible and distribute
pressure equally throughout your
whole body.
11. Where are some air spaces located in the body?
1/
22
, PADI Open Water Certification Study Guide
Ears, sinuses, lungs
2/
22
, PADI Open Water Certification Study Guide
12. Do you always feel the pressure in body air Only if the pressure is ditterent
inside and
spaces? outside the air spaces.
13. 1 bar is what depth? 0m/0ft
14. 2 bar is what depth? 33ft/10m
15. 3 bar is what depth? 66ft/20m
16. 4 bar is what depth? 99ft/30m
17. How is air volume affected when It decreases
depth is increased?
18. How is air density affected when
It increases
depth is increased?
19. What happens if you take an air
volume As pressure increases the volume
decreas-
underwater with you in a flexible container es, same air but smaller
space.
or inverted jar?
20. How do you maintain air volume as Equalize
you descend?
21. What is a "squeeze"? As volume decreases, pressure
pushes body tissues inwards
toward air space, causing
discomfort. Pressure outside air
space is more than pressure
inside air space.
22. Where can you get a squeeze? Ears, sinuses, mask, lungs, teeth
3/
22
