Padi Open Water Section 1 Flashcards
Because water is much denser and heavier than air, _________ exerts the same pressure as the whole atmosphere.
10 metres/33 feet
Depth 0m/0ft, pressure, volume, density
1 bar/ata, 1, x2
Depth 10m/33ft, pressure, volume, density
2 bar/ata, 1/2, x2
Depth 20m/66ft, pressure, volume, density
3 bar/ata, 1/3, x3
Depth 30m/99ft, pressure, volume, density
4 bar/ata, 1/4, x4
Depth 40m/132ft, pressure, volume, density
5 bar/ata, 1/5, x5
As the pressure increases – as you go deeper – a gas volume decreases because the gas molecules get compressed. This affects your
ears, sinuses, lungs, mask and, when using one, a dry suit.
The three major body spaces affected by pressure changes are
Ears, Sinuses, Mask
A squeeze is when
there is greater pressure outside the air space than inside it.
Prevent squeezes by
equalizing, which is prevent squeezes adding air to air spaces as you descend.
To equalize your ears and sinuses, you
pinch your nose and blow gently against it. You can also wiggle your jaws side to side and swallow.
To equalize your mask,
blow air into it through your nose as you descend.
How often should you equalize?
Every metre/few feet, before you feel discomfort
If you can’t equalize even after ascending a little…
stop your descent immediately. Signal your buddy(ies) or instructor.
If you can’t equalize at first,
Ascend slightly until the discomfort passes and try again. Be patient. After you equalize, descend more slowly, equalizing more frequently.
