SDI Exam UPDATED ACTUAL Exam
Questions and CORRECT Answers
Objects under water appear: - CORRECT ANSWER - Closer and larger than they do on
land
What happens to colors under water - CORRECT ANSWER - As you descend, colors
appear to fade, not intensify. Blues and grays are the last remaining colors at depth.
Because sound travels faster under water: - CORRECT ANSWER - Sound's increases
speed under water makes it harder to determine the direction from which it is coming.
Water conducts heat away from your body ___ times faster than air does - CORRECT
ANSWER - 25
The presence of thermoclines means that - CORRECT ANSWER - divers may require
more in the way of exposure protection at depth than they will at the surface.
Tides can: - CORRECT ANSWER - - make water seem deeper or shallower, stronger and
difficult, adverse effect on visibility
Cause of permanent ocean currents - CORRECT ANSWER - The sun warming water near
the equator, coupled with the earth's rotation, is the primary cause of permanent ocean currents.
Wave height and length - CORRECT ANSWER - Wave height is the distance from its
highest point (crest) to its lowest point (trough). Wave length is the distance from crest to crest.
formation of surf - CORRECT ANSWER - A wave encountering shallow water begins to
slow at its bottom, while the top of the wave continues at its previous speed. This causes the
wave to break.
, what is surge - CORRECT ANSWER - Surge is the back-and-forth movement of water
caused by waves passing over head.
What causes most aquatic animal bites? - CORRECT ANSWER - An animal's defensive
response to a perceived threat & mistaken identity
To be injured by an animal with poisonous spines, you must: - CORRECT ANSWER - Be
the aggressor and touch the animal first.
The states of buoyancy include all of the following except: - CORRECT ANSWER -
Passive
If you feel pain or discomfort during descent: - CORRECT ANSWER - Ascend to the
point where you can comfortably equalize, and only then continue your descent.
Which of the following is the best way to prevent or reduce nitrogen narcosis? - CORRECT
ANSWER -
Any time you cannot inhale while scuba diving (such as when a regulator is out of your mouth),
you must be - CORRECT ANSWER - Exhaling.
What can help prevent decompression sickness (DCS) - CORRECT ANSWER - safety
stops, Remain well within your dive computer's no-decompression limit, Ascend no faster than
the rate allowed by the dive computer
Contributing factors to decompression sickness can include: - CORRECT ANSWER -
Rapid ascents, 'Pushing" or exceeding your computer's no-decompression limits, Heavy exertion
and/or dehydration.
best way to prevent or reduce nitrogen narcosis? - CORRECT ANSWER - Avoid dives
below 20 meters/66 feet.
Questions and CORRECT Answers
Objects under water appear: - CORRECT ANSWER - Closer and larger than they do on
land
What happens to colors under water - CORRECT ANSWER - As you descend, colors
appear to fade, not intensify. Blues and grays are the last remaining colors at depth.
Because sound travels faster under water: - CORRECT ANSWER - Sound's increases
speed under water makes it harder to determine the direction from which it is coming.
Water conducts heat away from your body ___ times faster than air does - CORRECT
ANSWER - 25
The presence of thermoclines means that - CORRECT ANSWER - divers may require
more in the way of exposure protection at depth than they will at the surface.
Tides can: - CORRECT ANSWER - - make water seem deeper or shallower, stronger and
difficult, adverse effect on visibility
Cause of permanent ocean currents - CORRECT ANSWER - The sun warming water near
the equator, coupled with the earth's rotation, is the primary cause of permanent ocean currents.
Wave height and length - CORRECT ANSWER - Wave height is the distance from its
highest point (crest) to its lowest point (trough). Wave length is the distance from crest to crest.
formation of surf - CORRECT ANSWER - A wave encountering shallow water begins to
slow at its bottom, while the top of the wave continues at its previous speed. This causes the
wave to break.
, what is surge - CORRECT ANSWER - Surge is the back-and-forth movement of water
caused by waves passing over head.
What causes most aquatic animal bites? - CORRECT ANSWER - An animal's defensive
response to a perceived threat & mistaken identity
To be injured by an animal with poisonous spines, you must: - CORRECT ANSWER - Be
the aggressor and touch the animal first.
The states of buoyancy include all of the following except: - CORRECT ANSWER -
Passive
If you feel pain or discomfort during descent: - CORRECT ANSWER - Ascend to the
point where you can comfortably equalize, and only then continue your descent.
Which of the following is the best way to prevent or reduce nitrogen narcosis? - CORRECT
ANSWER -
Any time you cannot inhale while scuba diving (such as when a regulator is out of your mouth),
you must be - CORRECT ANSWER - Exhaling.
What can help prevent decompression sickness (DCS) - CORRECT ANSWER - safety
stops, Remain well within your dive computer's no-decompression limit, Ascend no faster than
the rate allowed by the dive computer
Contributing factors to decompression sickness can include: - CORRECT ANSWER -
Rapid ascents, 'Pushing" or exceeding your computer's no-decompression limits, Heavy exertion
and/or dehydration.
best way to prevent or reduce nitrogen narcosis? - CORRECT ANSWER - Avoid dives
below 20 meters/66 feet.
