Chapter 5

Question 1

What are the 3 states of buoyancy?

Answer 1

1. Positive Buoyancy: Objects that weigh less than the water they displace float.
2. Negative Buoyancy: Objects that weigh more than the water they displace sink.
3. Neutral Buoyancy: Objects that weigh exactly the same as the water they displace neither float nor sink.

Question 2

Does fresh or salt water weigh more?

Answer 2

Salt water weighs more than an equal volume of fresh water.

Question 3

What is the relationship between the pressure, volume of a gas in a flexible container?

Answer 3

Boyles law: The volume of gas in the lungs is inversely proportional to the increase or decrease in ambient pressure. At a depth of 2 atmospheres (10 m/33 ft), this volume will be half of what it was at the surface.

Question 4

How does this impact air consumption under water?

Answer 4

The deeper a diver goes, the more air molecules each lungful of air contains, and the faster the diver will go through the tank.

Question 5

What

Question 6

How does the pressure increase for every 10 m/33 ft of depth?

Answer 6

The pressure increases by one atmosphere of pressure.

Question 7

Why should divers equalize pressure on decent?

Answer 7

Divers should equalize pressure on decent to prevent ear squeeze.

Question 8

How should divers equalize pressure?

Answer 8

1. Valsalva Maneuver: Block the regulator mouthpiece with your tongue, pinching off your nostrils and blowing gently.
2. Yawning, swallowing or moving your jaw from side to side.

Question 9

When should a diver equalize pressure?

Answer 9

1. Divers should equalize preemptively on decent by beginning before leaving the surface.
2. Divers should equalize at least twice for every meter/3 feet of decent.

Question 10

What other types of squeezes may divers be subjected to?

Answer 10

1. Sinus Squeeze: When the sinuses fill with blood or mucus in an effort to equalize pressure.
2. Mask Squeeze: The mask pressurizes against the diver’s face.
3. Tooth Squeeze: When a tooth filling has a pocket of trapped air.
4. Reverse Block: When air cannot escape freely from an air space during ascent.

Question 11

How do you prevent or treat those squeezes?

Answer 11

1. Sinus Squeeze: A diver has to abort the dive.
2. Mask Squeeze: Exhale every few feet during descent.
3. Tooth Squeeze: A diver has to abort the dive.
4. Reverse Block: Descend until the pain subsides, yawn and/or swallow to stretch the eustachian tubes, wait a moment, and continue your ascent.

Question 12

What is the number one rule of scuba diving?

Answer 12

Breath continuously; never hold your breath.

Question 13

What are the possible consequences of holding your breath while asenting?

Answer 13

A lung over-expansion.

Question 14

How much does ambient pressure increase for every 10 m/33 ft of descent in seawater?

Answer 14

It increases by one atmosphere.