SDI Open Water ACTUAL UPDATED
Exam Questions and CORRECT Answers
What is the absolute pressure (in atm) at 66 feet? - CORRECT ANSWER - 2 atm
What will be the volume in a ball that is filled with two cubic feet of air at 99 feet when it's taken
to the surface? - CORRECT ANSWER - 8 cubic feet
How many more times dense is the air in a balloon at 4 atm compared to the air density at the
surface? - CORRECT ANSWER - 4 X as dense
What is the abbreviation for an atmosphere? - CORRECT ANSWER - atm
If a scuba cylindar lasts 2 hours (120 minutes) at sea level, how long will it last at 66 feet? -
CORRECT ANSWER - 40 minutes
How often should a diver equalize during a descent? - CORRECT ANSWER - Early and
often
What should you do if you experience discomfort in your ears while descending? - CORRECT
ANSWER - Stop descent, ascend a few feet. Equalize, then descend again.
What is a reverse block? - CORRECT ANSWER - Pressure caused by air spaces in your
body expanding during ascent.
What is squeeze? - CORRECT ANSWER - The painful compression of air spaces in your
body or equipment during descent.
, What should you do if you experience a reverse block upon ascending? - CORRECT
ANSWER - Descend a few feet until the pain subsides. Wait a few moments. Then, ascend
again.
What is the most important rule in scuba diving? - CORRECT ANSWER - Never hold
your breath!
What is the most serious injury that a diver can suffer from if they hold their breath while
ascending? - CORRECT ANSWER - Lung over-expansion injury (possibly fatal)
Which gas component in air causes decompression sickness and narcosis? - CORRECT
ANSWER - Nitrogen
What medical problem can occur if a diver ascends much too rapidly for nitrogen to be slowly
released, or off-gassed? - CORRECT ANSWER - Decompression Sickness
List at least 5 factors that can predispose a diver to decompression sickness. - CORRECT
ANSWER - 1. Obesity
2. Age
3. Illness
4. Past/Present Injuries
5. Prior History of DCS
6. Fatigue
7. Dehydration
8. Smoke inhalation
9. Use of drugs/alcohol prior to dive
10. Repetative Dives
11. Overexertion
12. Cold Water
13. Diving at higher altitudes
Exam Questions and CORRECT Answers
What is the absolute pressure (in atm) at 66 feet? - CORRECT ANSWER - 2 atm
What will be the volume in a ball that is filled with two cubic feet of air at 99 feet when it's taken
to the surface? - CORRECT ANSWER - 8 cubic feet
How many more times dense is the air in a balloon at 4 atm compared to the air density at the
surface? - CORRECT ANSWER - 4 X as dense
What is the abbreviation for an atmosphere? - CORRECT ANSWER - atm
If a scuba cylindar lasts 2 hours (120 minutes) at sea level, how long will it last at 66 feet? -
CORRECT ANSWER - 40 minutes
How often should a diver equalize during a descent? - CORRECT ANSWER - Early and
often
What should you do if you experience discomfort in your ears while descending? - CORRECT
ANSWER - Stop descent, ascend a few feet. Equalize, then descend again.
What is a reverse block? - CORRECT ANSWER - Pressure caused by air spaces in your
body expanding during ascent.
What is squeeze? - CORRECT ANSWER - The painful compression of air spaces in your
body or equipment during descent.
, What should you do if you experience a reverse block upon ascending? - CORRECT
ANSWER - Descend a few feet until the pain subsides. Wait a few moments. Then, ascend
again.
What is the most important rule in scuba diving? - CORRECT ANSWER - Never hold
your breath!
What is the most serious injury that a diver can suffer from if they hold their breath while
ascending? - CORRECT ANSWER - Lung over-expansion injury (possibly fatal)
Which gas component in air causes decompression sickness and narcosis? - CORRECT
ANSWER - Nitrogen
What medical problem can occur if a diver ascends much too rapidly for nitrogen to be slowly
released, or off-gassed? - CORRECT ANSWER - Decompression Sickness
List at least 5 factors that can predispose a diver to decompression sickness. - CORRECT
ANSWER - 1. Obesity
2. Age
3. Illness
4. Past/Present Injuries
5. Prior History of DCS
6. Fatigue
7. Dehydration
8. Smoke inhalation
9. Use of drugs/alcohol prior to dive
10. Repetative Dives
11. Overexertion
12. Cold Water
13. Diving at higher altitudes
