SDI Open Water Exam Questions and
Answers
Question 1
How do you vent air from a BCD?
Correct Answer
By holding the end of your inflator hose over your head and depressing the inflator
button.
Question 2
What is the first color to be absorbed underwater?
Correct Answer
Red is the first color to disappear under water.
Question 3
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.
Question 4
A. How much faster does sound move underwater than in the air?
B. Why is this important to a diver?
Correct Answer
A. Sound moves 4X faster in water than air due to the density of the water.
B. It's difficult for the diver to tell which direction sound is coming from, or how far
away it is. This can be especially dangerous when you hear a boat overhead.
Page 1 of 36
,Question 5
What extra attire can enhance a divers warmth when worn with a wet suit or a dry
suit?
Correct Answer
1. Neoprene boots 2. Gloves 3. Hoods.
Question 6
What are 2 types of weight systems?
Correct Answer
1. Belts 2. Pouches on the BCD
Question 7
A cylindar should be visually inspected at least XXX a year and hydrostatically tested
every XXX years in the United States.
Correct Answer
1. once a year 2. every five years
Question 8
When planning a repetitive dive, the _________ diver should be made first.
Correct Answer
deeper
Question 9
A. How much larger and closer do items appear underwater?
B. Why is this important to a diver?
Correct Answer
A. 33% Larger and 25% Closer
B. Visual distortion may be disorienting to a diver and can cause dizziness.
Page 2 of 36
,Question 10
You are wearing a 1/4" wetsuit, you have left the surface and descent has begun. You
will need to do what? Explain your choice.
(A) Change the weights on the weight belt
(B) Let the air out of the BCD
(C) Add air to the BCD
Correct Answer
(C) Add air to the BCD
The deeper you descend the more the cells in the wet suit compress thus displacing
less water. When this happens you become less buoyant and will need to add air to
the BCD to bring yourself back to neutral buoyancy.
Question 11
What is a reverse block?
Correct Answer
Pressure caused by air spaces in your body expanding during ascent.
Question 12
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.
Question 13
List 4 functions of a dive computer.
Correct Answer
1. No Decompression Limit 2. Current Depth 3. Max Depth 4. Dive Time 5. Ascent
Rate 6. Required Decompression 7. Surface Interval Time 8. Time to Fly 9. Logbook
10. Bottom Time
Page 3 of 36
, Question 14
What is the emergency procedure for suspected decompression sickness?
Correct Answer
1. Move the affected diver out of danger.
2. Activate the Emergency Medical System (EMS)
3. Monitor life support signs (pulse and respiration) and provide CPR if necessary.
4. Provide 100% O2 via demand regulator if the diver is breathing.
5. Evacuation if necessary
Question 15
A. Water conducts heat away from the body about XXX percent faster than air.
B. Why does this matter to a diver?
Correct Answer
A. 25%
B. It's much easier to experience cold related injuries (such as hypothermia)
underwater than on land. Always plan ahead and wear a wetsuit or drysuit as
necessary to prevent injury.
Question 16
Atmospheric pressure is 14.7 PSI at sea level. What is the absolute pressure at a depth
of 33 feet?
Correct Answer
29.4 PSI
Question 17
When diving from the shore, the best time to dive is when there is the least amount
of tidal current. XXX tide is when there is no horizontal water movement.
Correct Answer
Slack
Page 4 of 36
Answers
Question 1
How do you vent air from a BCD?
Correct Answer
By holding the end of your inflator hose over your head and depressing the inflator
button.
Question 2
What is the first color to be absorbed underwater?
Correct Answer
Red is the first color to disappear under water.
Question 3
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.
Question 4
A. How much faster does sound move underwater than in the air?
B. Why is this important to a diver?
Correct Answer
A. Sound moves 4X faster in water than air due to the density of the water.
B. It's difficult for the diver to tell which direction sound is coming from, or how far
away it is. This can be especially dangerous when you hear a boat overhead.
Page 1 of 36
,Question 5
What extra attire can enhance a divers warmth when worn with a wet suit or a dry
suit?
Correct Answer
1. Neoprene boots 2. Gloves 3. Hoods.
Question 6
What are 2 types of weight systems?
Correct Answer
1. Belts 2. Pouches on the BCD
Question 7
A cylindar should be visually inspected at least XXX a year and hydrostatically tested
every XXX years in the United States.
Correct Answer
1. once a year 2. every five years
Question 8
When planning a repetitive dive, the _________ diver should be made first.
Correct Answer
deeper
Question 9
A. How much larger and closer do items appear underwater?
B. Why is this important to a diver?
Correct Answer
A. 33% Larger and 25% Closer
B. Visual distortion may be disorienting to a diver and can cause dizziness.
Page 2 of 36
,Question 10
You are wearing a 1/4" wetsuit, you have left the surface and descent has begun. You
will need to do what? Explain your choice.
(A) Change the weights on the weight belt
(B) Let the air out of the BCD
(C) Add air to the BCD
Correct Answer
(C) Add air to the BCD
The deeper you descend the more the cells in the wet suit compress thus displacing
less water. When this happens you become less buoyant and will need to add air to
the BCD to bring yourself back to neutral buoyancy.
Question 11
What is a reverse block?
Correct Answer
Pressure caused by air spaces in your body expanding during ascent.
Question 12
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.
Question 13
List 4 functions of a dive computer.
Correct Answer
1. No Decompression Limit 2. Current Depth 3. Max Depth 4. Dive Time 5. Ascent
Rate 6. Required Decompression 7. Surface Interval Time 8. Time to Fly 9. Logbook
10. Bottom Time
Page 3 of 36
, Question 14
What is the emergency procedure for suspected decompression sickness?
Correct Answer
1. Move the affected diver out of danger.
2. Activate the Emergency Medical System (EMS)
3. Monitor life support signs (pulse and respiration) and provide CPR if necessary.
4. Provide 100% O2 via demand regulator if the diver is breathing.
5. Evacuation if necessary
Question 15
A. Water conducts heat away from the body about XXX percent faster than air.
B. Why does this matter to a diver?
Correct Answer
A. 25%
B. It's much easier to experience cold related injuries (such as hypothermia)
underwater than on land. Always plan ahead and wear a wetsuit or drysuit as
necessary to prevent injury.
Question 16
Atmospheric pressure is 14.7 PSI at sea level. What is the absolute pressure at a depth
of 33 feet?
Correct Answer
29.4 PSI
Question 17
When diving from the shore, the best time to dive is when there is the least amount
of tidal current. XXX tide is when there is no horizontal water movement.
Correct Answer
Slack
Page 4 of 36