SDI Open Water Set
What should you do if you experience discomfort in your ears while descending? -
✔️✔️Stop descent, ascend a few feet. Equalize, then descend again.
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? - ✔️✔️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? - ✔️✔️4 X as dense
What is the abbreviation for an atmosphere? - ✔️✔️atm
If a scuba cylindar lasts 2 hours (120 minutes) at sea level, how long will it last at 66
feet? - ✔️✔️40 minutes
How often should a diver equalize during a descent? - ✔️✔️Early and often
What is a reverse block? - ✔️✔️Pressure caused by air spaces in your body expanding
during ascent.
What is squeeze? - ✔️✔️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? -
✔️✔️Descend a few feet until the pain subsides. Wait a few moments. Then, ascend
again.
What is the most important rule in scuba diving? - ✔️✔️Never hold your breath!
What is the most serious injury that a diver can suffer from if they hold their breath while
ascending? - ✔️✔️Lung over-expansion injury (possibly fatal)
What is the absolute pressure (in atm) at 66 feet? - ✔️✔️2 atm
Which gas component in air causes decompression sickness and narcosis? -
✔️✔️Nitrogen
, List at least 5 factors that can predispose a diver to decompression sickness. - ✔️✔️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
Describe the symptoms of DCS, including mild to severe signs and symptoms. -
✔️✔️1. Rash or Crackling Skin
2. Joint Pain (most common symptom)
3. Difficulty Breathing
4. Cough
5. Numbness
6. Dizziness
7. Tingling
8. Paralysis
9. Temporary Blindness
10. Unconciousness
What is the depth threshold where most scuba divers begin to be affected by nitrogen
narcosis? - ✔️✔️100 feet
List two possible ways a diver may feel if they become "narked" at depth. -
✔️✔️Extreme Euphoria
Extreme Anxiety
What should a diver do to alleviate the symptoms of nitrogen narcosis? - ✔️✔️Ascend
normally until you no longer feel the affects
Which gas causes extreme headache and nausea, and in high enough concentrations
causes unconciousness and the lips and fingernails to turn bright red? - ✔️✔️Carbon
Monoxide
What may indicate that the air in a scuba cylinder is dangerous to breath? - ✔️✔️Odor
or Taste
What should you do if you experience discomfort in your ears while descending? -
✔️✔️Stop descent, ascend a few feet. Equalize, then descend again.
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? - ✔️✔️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? - ✔️✔️4 X as dense
What is the abbreviation for an atmosphere? - ✔️✔️atm
If a scuba cylindar lasts 2 hours (120 minutes) at sea level, how long will it last at 66
feet? - ✔️✔️40 minutes
How often should a diver equalize during a descent? - ✔️✔️Early and often
What is a reverse block? - ✔️✔️Pressure caused by air spaces in your body expanding
during ascent.
What is squeeze? - ✔️✔️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? -
✔️✔️Descend a few feet until the pain subsides. Wait a few moments. Then, ascend
again.
What is the most important rule in scuba diving? - ✔️✔️Never hold your breath!
What is the most serious injury that a diver can suffer from if they hold their breath while
ascending? - ✔️✔️Lung over-expansion injury (possibly fatal)
What is the absolute pressure (in atm) at 66 feet? - ✔️✔️2 atm
Which gas component in air causes decompression sickness and narcosis? -
✔️✔️Nitrogen
, List at least 5 factors that can predispose a diver to decompression sickness. - ✔️✔️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
Describe the symptoms of DCS, including mild to severe signs and symptoms. -
✔️✔️1. Rash or Crackling Skin
2. Joint Pain (most common symptom)
3. Difficulty Breathing
4. Cough
5. Numbness
6. Dizziness
7. Tingling
8. Paralysis
9. Temporary Blindness
10. Unconciousness
What is the depth threshold where most scuba divers begin to be affected by nitrogen
narcosis? - ✔️✔️100 feet
List two possible ways a diver may feel if they become "narked" at depth. -
✔️✔️Extreme Euphoria
Extreme Anxiety
What should a diver do to alleviate the symptoms of nitrogen narcosis? - ✔️✔️Ascend
normally until you no longer feel the affects
Which gas causes extreme headache and nausea, and in high enough concentrations
causes unconciousness and the lips and fingernails to turn bright red? - ✔️✔️Carbon
Monoxide
What may indicate that the air in a scuba cylinder is dangerous to breath? - ✔️✔️Odor
or Taste
