Page |1
SDI SCUBA CERTIFICATION EXAM STUDY
GUIDE 2025 ACTUAL EXAM QUESTIONS
WITH 100% CORRECT SOLUTIONS |
GUARANTEED SUCCESS.
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? - Correct Answer-Decompression sickness
blood flow becomes blocked by Nitrogen bubbles
List five factors that can predispose a diver to decompression sickness -
Correct Answer-1) age
2) repetitive dives
3) illness
4) obesity
5) drug and/or alcohol use prior to dive
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Describe symptoms of decompression sickness (include mild and severe
signs and symptoms) - Correct Answer-Rash or crackling skin caused by
nitrogen bubbles in skin capillaries
joint pain caused by bubbles collecting in and around joints
difficulty breathing
loss of sensation (numbness)
unconsciousness
paralysis
What is the depth threshold where most scuba divers generally begin to be
affected by nitrogen narcosis? - Correct Answer-30 meters sea water/100
feet sea water
List two possible ways a diver may feel if they become "narked" at depth -
Correct Answer-Extreme Euphoria
Anxiety
What should a diver do to alleviate the symptoms of nitrogen narcosis? -
Correct Answer-Ascend normally until you no longer feel the affects
Which gas causes extreme headache and nausea, and in high enough
concentrations causes unconsciousness and the lips and fingernail beds
turn bright red? - Correct Answer-Carbon monoxide (CO)
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What may indicate that the air in a scuba cylinder is harmful to consume? -
Correct Answer-Air has an odor or foul taste
what should you do if you suddenly feel sick and develop a headache
during a scuba dive? - Correct Answer-Abort dive with a controlled ascent
Breathe fresh air
What is the main purpose of a snorkel? - Correct Answer-It's used when a
long swim on the surface is required in order to conserve air in the tanks.
How do you know if a mask fits properly? - Correct Answer-try on without
strap by placing over eyes and breathing in through nose - If tightens
against face and does not fall off, it is a proper fit
Define SCUBA - Correct Answer-S - self
C - contained
U - underwater
B - breathing
A - apparatus
List 3 important scuba diving changes that occurred in 1950s - Correct
Answer-1) published USN dive tables
SDI SCUBA CERTIFICATION EXAM STUDY
GUIDE 2025 ACTUAL EXAM QUESTIONS
WITH 100% CORRECT SOLUTIONS |
GUARANTEED SUCCESS.
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? - Correct Answer-Decompression sickness
blood flow becomes blocked by Nitrogen bubbles
List five factors that can predispose a diver to decompression sickness -
Correct Answer-1) age
2) repetitive dives
3) illness
4) obesity
5) drug and/or alcohol use prior to dive
, Page |2
Describe symptoms of decompression sickness (include mild and severe
signs and symptoms) - Correct Answer-Rash or crackling skin caused by
nitrogen bubbles in skin capillaries
joint pain caused by bubbles collecting in and around joints
difficulty breathing
loss of sensation (numbness)
unconsciousness
paralysis
What is the depth threshold where most scuba divers generally begin to be
affected by nitrogen narcosis? - Correct Answer-30 meters sea water/100
feet sea water
List two possible ways a diver may feel if they become "narked" at depth -
Correct Answer-Extreme Euphoria
Anxiety
What should a diver do to alleviate the symptoms of nitrogen narcosis? -
Correct Answer-Ascend normally until you no longer feel the affects
Which gas causes extreme headache and nausea, and in high enough
concentrations causes unconsciousness and the lips and fingernail beds
turn bright red? - Correct Answer-Carbon monoxide (CO)
, Page |3
What may indicate that the air in a scuba cylinder is harmful to consume? -
Correct Answer-Air has an odor or foul taste
what should you do if you suddenly feel sick and develop a headache
during a scuba dive? - Correct Answer-Abort dive with a controlled ascent
Breathe fresh air
What is the main purpose of a snorkel? - Correct Answer-It's used when a
long swim on the surface is required in order to conserve air in the tanks.
How do you know if a mask fits properly? - Correct Answer-try on without
strap by placing over eyes and breathing in through nose - If tightens
against face and does not fall off, it is a proper fit
Define SCUBA - Correct Answer-S - self
C - contained
U - underwater
B - breathing
A - apparatus
List 3 important scuba diving changes that occurred in 1950s - Correct
Answer-1) published USN dive tables
