What are the 3 states of buoyancy?
- Positive Buoyancy: Objects that weigh less than the water they displace float.
- Negative Buoyancy: Objects that weigh more than the water they displace sink.
- Neutral Buoyancy: Objects that weigh exactly the same as the water they displace neither float nor sink.
Does fresh or salt water weigh more?
Salt water weighs more than an equal volume of fresh water.
What is the relationship between the pressure, volume of a gas in a flexible container?
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.
How does this impact air consumption under water?
The deeper a diver goes, the more air molecules each lungful of air contains, and the faster the diver will go through the tank.
What
How does the pressure increase for every 10 m/33 ft of depth?
The pressure increases by one atmosphere of pressure.
Why should divers equalize pressure on decent?
Divers should equalize pressure on decent to prevent ear squeeze.
How should divers equalize pressure?
- Valsalva Maneuver: Block the regulator mouthpiece with your tongue, pinching off your nostrils and blowing gently.
- Yawning, swallowing or moving your jaw from side to side.
When should a diver equalize pressure?
- Divers should equalize preemptively on decent by beginning before leaving the surface.
- Divers should equalize at least twice for every meter/3 feet of decent.
What other types of squeezes may divers be subjected to?
- Sinus Squeeze: When the sinuses fill with blood or mucus in an effort to equalize pressure.
- Mask Squeeze: The mask pressurizes against the diver’s face.
- Tooth Squeeze: When a tooth filling has a pocket of trapped air.
- Reverse Block: When air cannot escape freely from an air space during ascent.
How do you prevent or treat those squeezes?
- Sinus Squeeze: A diver has to abort the dive.
- Mask Squeeze: Exhale every few feet during descent.
- Tooth Squeeze: A diver has to abort the dive.
- Reverse Block: Descend until the pain subsides, yawn and/or swallow to stretch the eustachian tubes, wait a moment, and continue your ascent.
What is the number one rule of scuba diving?
Breath continuously; never hold your breath.
What are the possible consequences of holding your breath while asenting?
A lung over-expansion.
How much does ambient pressure increase for every 10 m/33 ft of descent in seawater?
It increases by one atmosphere.
