Q: Depth 20m/66ft what is the pressure, volume and density 

Answer: 

3. bar/ata, 1/3 volume, 3x density 

Q: Depth 30m/99ft what is the pressure, volume and density 

Answer: 

4. bar/ata, 1/4 volume, 4x density 

Q: As I descend, I need to equalize air spaces. Which of the following are accepted ways of equalizing my ears? 

1. Block my nose and attempt to gently blow through it. 

2. Swallow and wiggle the jaw from side to side 

3. Block my nose and blow forcefully for an extended period 

Answer: 

Block my nose and attempt to gently blow through it + swallow and wiggle the jaw from side to side 

Q: I should equalize 

1. early and often, before I feel discomfort 

2. when I begin to feel discomfort 

3. only if I experience pain