SCUBA - ANSWER Self contained underwater breathing apparatus
What is the pressure change for each 10m/33ft of depth change? - ANSWER 1 bar/1
ata/1 atmosphere
What is the relationship between my depth in water and the pressure? - ANSWER The
deeper you go in water, the more the pressure increases
Pressure is expressed as the weight of air
What is the relationship between pressure, and the volume and the density of air? - AN-
SWER As pressure increases, the gas volume decreases and the gas density increases
If I take a volume of air from one depth to another depth, how much will the volume and
density change? - ANSWER Volume will be 1/ata#
Density will be ata#
What 3 major body air spaces does increasing pressure affect as I descend? - ANSWER
Ears, sinuses, mask
What is a "squeeze"? - ANSWER The discomfort caused by pressure imbalance pulling tis-
sue into the air space
What is "equalization"? - ANSWER The addition of air to your air spaces as you descend
1
,How do I equalize as I descend? - ANSWER For ears and sinuses, pinch your nose and
blow gently, or wiggle your jaw and swallow
For mask, blow into it with nose
How often should I equalize? - ANSWER Every meter/few feet, BEFORE you feel discom-
fort
What should I do if I can't equalize? - ANSWER Stop your descent, signal problem and
point to your ear, ascend a bit, and try again
What can happen if I don't or can't equalize gently and keep descending? - ANSWER Fluid
can rupture the eardrum
Bruising around the face can occur
Why does a congestion from a cold or allergy temporarily keep me from diving? - AN-
SWER Congestion might block normal air flow, making equalization difficult or impossible
Why should I never dive with earplugs? - ANSWER They create air spaces that you can't
equalize
What other body air spaces are affected by increasing pressure? How do I equalize them? -
ANSWER In filled teeth - go to a dentist
In a dry suit - learn from an instructor
Lungs - breathe normally and continuously
What is the most important rule in scuba diving? - ANSWER Breathe continuously and
never hold your breath
What can happen if I don't follow the most important rule in scuba diving? - ANSWER
Your lungs will over expand and rupture
2
, What is a "reverse block"? - ANSWER When expanding air becomes trapped in your body
air spaces as you ascend
What should I do if I feel discomfort in my ears, sinuses, stomach, intestines, or teeth while
ascending? - ANSWER Stop your ascent and descend a meter/few feet to reduce discom-
fort and give trapped air time to work its way out
How does depth affect how long my air supply lasts? - ANSWER The deeper you are, the
more dense air you breathe, and the faster you use the air in your cylinder. Compared to the
surface, air supply lasts 1/#ata as long along with other factors
What's the most efficient way to breathe dense air underwater? - ANSWER Take slow,
deep breaths
How do I breathe to reduce anxiety when under stress? - ANSWER Do NOT breathe faster
- keep breathing slowly
What are my 4 breathing rules as a scuba diver? - ANSWER 1. Breathe continuously and
never hold your breath
2. Breathe slowly and deeply
3. Don't allow yourself to get winded or out of breath
4. If faced with a problem, stop, and reduce anxiety by breathing slowly and deeply
What is buoyancy? - ANSWER An upward force acting on an object in the water, canceling
the pull of gravity
What causes buoyancy? - ANSWER The upwards force is caused by the water displaced
by the object, and is equal to the weight of displaced water
3
What is the pressure change for each 10m/33ft of depth change? - ANSWER 1 bar/1
ata/1 atmosphere
What is the relationship between my depth in water and the pressure? - ANSWER The
deeper you go in water, the more the pressure increases
Pressure is expressed as the weight of air
What is the relationship between pressure, and the volume and the density of air? - AN-
SWER As pressure increases, the gas volume decreases and the gas density increases
If I take a volume of air from one depth to another depth, how much will the volume and
density change? - ANSWER Volume will be 1/ata#
Density will be ata#
What 3 major body air spaces does increasing pressure affect as I descend? - ANSWER
Ears, sinuses, mask
What is a "squeeze"? - ANSWER The discomfort caused by pressure imbalance pulling tis-
sue into the air space
What is "equalization"? - ANSWER The addition of air to your air spaces as you descend
1
,How do I equalize as I descend? - ANSWER For ears and sinuses, pinch your nose and
blow gently, or wiggle your jaw and swallow
For mask, blow into it with nose
How often should I equalize? - ANSWER Every meter/few feet, BEFORE you feel discom-
fort
What should I do if I can't equalize? - ANSWER Stop your descent, signal problem and
point to your ear, ascend a bit, and try again
What can happen if I don't or can't equalize gently and keep descending? - ANSWER Fluid
can rupture the eardrum
Bruising around the face can occur
Why does a congestion from a cold or allergy temporarily keep me from diving? - AN-
SWER Congestion might block normal air flow, making equalization difficult or impossible
Why should I never dive with earplugs? - ANSWER They create air spaces that you can't
equalize
What other body air spaces are affected by increasing pressure? How do I equalize them? -
ANSWER In filled teeth - go to a dentist
In a dry suit - learn from an instructor
Lungs - breathe normally and continuously
What is the most important rule in scuba diving? - ANSWER Breathe continuously and
never hold your breath
What can happen if I don't follow the most important rule in scuba diving? - ANSWER
Your lungs will over expand and rupture
2
, What is a "reverse block"? - ANSWER When expanding air becomes trapped in your body
air spaces as you ascend
What should I do if I feel discomfort in my ears, sinuses, stomach, intestines, or teeth while
ascending? - ANSWER Stop your ascent and descend a meter/few feet to reduce discom-
fort and give trapped air time to work its way out
How does depth affect how long my air supply lasts? - ANSWER The deeper you are, the
more dense air you breathe, and the faster you use the air in your cylinder. Compared to the
surface, air supply lasts 1/#ata as long along with other factors
What's the most efficient way to breathe dense air underwater? - ANSWER Take slow,
deep breaths
How do I breathe to reduce anxiety when under stress? - ANSWER Do NOT breathe faster
- keep breathing slowly
What are my 4 breathing rules as a scuba diver? - ANSWER 1. Breathe continuously and
never hold your breath
2. Breathe slowly and deeply
3. Don't allow yourself to get winded or out of breath
4. If faced with a problem, stop, and reduce anxiety by breathing slowly and deeply
What is buoyancy? - ANSWER An upward force acting on an object in the water, canceling
the pull of gravity
What causes buoyancy? - ANSWER The upwards force is caused by the water displaced
by the object, and is equal to the weight of displaced water
3
