NAUI Nitrox Diver Final Exam Questions with
Detailed Verified Answers
The main reason to dive with "nitrox" is to reduce exposure to some of the problems
in diving caused by: Ans: Nitrogen
We say that nitrogen is an inert gas. This means_____. Ans: Our bodies do not use
the nitrogen we breathe.
What is the primary safety hazard of breathing nitrogen at depth? Ans: Narcosis
NAUI sanctioned enriched air nitrox training in: Ans: 1992
Benefits of nitrox include: Ans: Extended bottom time
Increased safety margins
Shorter surface intervals
The greatest advantages for diving using nitrox occur in what depth range? Ans: 15- 33
msw (50-110 fsw)
True or False: A scuba diver breathing nitrox avoids any risk of nitrogen narcosis. Ans:
False
If a nitrox mix is 36% oxygen, what is the fraction of oxygen in the gas mix? Ans: 0.36
_____ describes the relationship between absolute pressure and the volume of a gas.
Ans: Boyle's Law
To find the partial pressure of a gas in a mixture: Ans: Multiply the gas fraction by the
absolute pressure.
The water pressure plus atmospheric pressure equals: Ans: Absolute pressure
What is the absolute pressure at 34 msw (111 fsw)? Ans: 4.4 ata
, What is the nitrogen partial pressure (PN2) in EAN35 at a depth of 26 msw (85 fsw)?
Ans: 2.3 ata
What is the oxygen partial pressure (PO2) of EAN38 at 27 msw (87 fsw)? Ans: 1.4 ata
At what depth in the ocean is the absolute pressure 6.4 ata? Ans: 54 msw (178 fsw)
If the PO2 at 30 msw (98 fsw) is 1.4 atmospheres, what is the oxygen fraction of the
breathing mixture? Ans: 0.35
What is the partial pressure of nitrogen in air at 40 msw (130 fsw)? Ans: 3.9 ata
True or False. Narcosis is reduced significantly when diving with enriched air nitrox.
Ans: False
The mechanisms of nitrogen narcosis are thought to be similar to: Ans: Anesthesia
Oxygen is used by the body in: Ans: Metabolism
The term used for low oxygen in the body is: Ans: Hypoxia
Breathing high partial pressures of oxygen can cause: Ans: Convulsions
The accepted oxygen partial pressure exposure limit for recreational nitrox diving is:
Ans: 1.4 ata
At the first signs or symptoms of oxygen toxicity, a diver should: Ans: Terminate the
dive.
Historically, what are the two standard nitrox mixes? Ans: 32% oxygen and 36%
oxygen
What is the "best mix" to use for an oxygen partial pressure limit of 1.4 ata on a dive
to 27 msw (90 fsw)? Ans: EAN38
© Get it right 2025 Getaway - Stuvia US All rights reserved
Detailed Verified Answers
The main reason to dive with "nitrox" is to reduce exposure to some of the problems
in diving caused by: Ans: Nitrogen
We say that nitrogen is an inert gas. This means_____. Ans: Our bodies do not use
the nitrogen we breathe.
What is the primary safety hazard of breathing nitrogen at depth? Ans: Narcosis
NAUI sanctioned enriched air nitrox training in: Ans: 1992
Benefits of nitrox include: Ans: Extended bottom time
Increased safety margins
Shorter surface intervals
The greatest advantages for diving using nitrox occur in what depth range? Ans: 15- 33
msw (50-110 fsw)
True or False: A scuba diver breathing nitrox avoids any risk of nitrogen narcosis. Ans:
False
If a nitrox mix is 36% oxygen, what is the fraction of oxygen in the gas mix? Ans: 0.36
_____ describes the relationship between absolute pressure and the volume of a gas.
Ans: Boyle's Law
To find the partial pressure of a gas in a mixture: Ans: Multiply the gas fraction by the
absolute pressure.
The water pressure plus atmospheric pressure equals: Ans: Absolute pressure
What is the absolute pressure at 34 msw (111 fsw)? Ans: 4.4 ata
, What is the nitrogen partial pressure (PN2) in EAN35 at a depth of 26 msw (85 fsw)?
Ans: 2.3 ata
What is the oxygen partial pressure (PO2) of EAN38 at 27 msw (87 fsw)? Ans: 1.4 ata
At what depth in the ocean is the absolute pressure 6.4 ata? Ans: 54 msw (178 fsw)
If the PO2 at 30 msw (98 fsw) is 1.4 atmospheres, what is the oxygen fraction of the
breathing mixture? Ans: 0.35
What is the partial pressure of nitrogen in air at 40 msw (130 fsw)? Ans: 3.9 ata
True or False. Narcosis is reduced significantly when diving with enriched air nitrox.
Ans: False
The mechanisms of nitrogen narcosis are thought to be similar to: Ans: Anesthesia
Oxygen is used by the body in: Ans: Metabolism
The term used for low oxygen in the body is: Ans: Hypoxia
Breathing high partial pressures of oxygen can cause: Ans: Convulsions
The accepted oxygen partial pressure exposure limit for recreational nitrox diving is:
Ans: 1.4 ata
At the first signs or symptoms of oxygen toxicity, a diver should: Ans: Terminate the
dive.
Historically, what are the two standard nitrox mixes? Ans: 32% oxygen and 36%
oxygen
What is the "best mix" to use for an oxygen partial pressure limit of 1.4 ata on a dive
to 27 msw (90 fsw)? Ans: EAN38
© Get it right 2025 Getaway - Stuvia US All rights reserved
