NAUI INSTRUCTOR EXAM 2025/2026
QUESTIONS AND ANSWERS 100% PASS
Henry's Law - ANS The amount of gas dissolved in a liquid is directly related to its partial
pressure above the liquid.
Relationship of gas solubility and temperature - ANS Solubility of gas decreases with
increasing temperature
(INVERSELY RELATED)
Inert gas loading in relation to body tissue - ANS Body tissue absorbs more inert gas as depth
increases
Benefit of Dive Computer compared to Dive Tables - ANS Gives the diver credit for shallow
portions of the dive
Cold or Strenuous dive planning rule - ANS Use the next greater dive TIME to determine
letter group
Equilibrium as it relates to nitrogen in the body - ANS When the pressure of nitrogen is
balanced between air and your body
Haldane surfacing ratio - ANS Originally 2:1 - Updated with new research to 1.58:1
1 @COPYRIGHT 2025/2026.
,Tissue compartment half-time - ANS The time required for the compartment to absorb or
eliminate half of the pressure difference between what it started with and the ambient
pressure
M-Value of tissue - ANS The maximum allowable nitrogen (inert gas) pressure in a specific
tissue
NAUI recommendation for diving while pregnant - ANS Do not dive while pregnant
Haldane tissue compartments - ANS Haldane - 5 compartments
Modern Computers - Apx. 16 compartments
Tissue compartment - ANS Mathematical model consisting of multiple theoretical tissues and
their relative halftimes
Fast compartments - short halftimes
Slow compartments - long halftimes
Ascent rate at altitude - ANS Slower than at sea level
Extend dive times with gas by - ANS Decreased nitrogen and increased oxygen in breathing
gas
RNT - ANS Residual Nitrogen Time
Tme already spent at the repetitive dive depth (dive tables)
Procedure for missed decompression stops - ANS Remain out of the water, rest, breathe
100% oxygen, drink fluids, be monitored for signs of decompression illness, transported to a
hyperbaric facility if symptoms arise
2 @COPYRIGHT 2025/2026.
, SIT - ANS Surface Interval Time
Longer time at the surface allows for increased repeat dive times
Canadian Dive Tables published by the Defense and Civil Institute of Environmental Medicine
(DCIEM) - ANS Based on 20+ years of research pioneered by Kidd and Stubbs (1962)
Swiss Dive Tables - ANS Developed by A.A. Bühlmann at the University of Zurich - EXTENDED
TO INCLUDE ALTITUDE DIVING
If the time spent making a "precautionary stop" at 5 msw (15 fsw) causes your Total Dive Time
to exceed the Dive Time Limits, you should: - ANS Use the Maximum Dive Time as your Total
Dive Time
Aching pains an hour after a dive might be: - ANS Decompression sickness
ATA rating for most hyperbaric chambers for treating divers: - ANS 6 ATA
Haldane Tissue Half-Times (Compartments) - ANS 5, 10, 20, 40, 75 Mins
High altitude dive - ANS Any dive at greater than 1000 feet
Ideal hyperbaric chamber for dive injury - ANS Multiplace, double-lock chamber rated for
service to six atmospheres
Repetitive Dive - ANS Any dive started within 24 hours after a previous dive
NAUI recommended minimum SIT time - ANS 60 mins
3 @COPYRIGHT 2025/2026.
QUESTIONS AND ANSWERS 100% PASS
Henry's Law - ANS The amount of gas dissolved in a liquid is directly related to its partial
pressure above the liquid.
Relationship of gas solubility and temperature - ANS Solubility of gas decreases with
increasing temperature
(INVERSELY RELATED)
Inert gas loading in relation to body tissue - ANS Body tissue absorbs more inert gas as depth
increases
Benefit of Dive Computer compared to Dive Tables - ANS Gives the diver credit for shallow
portions of the dive
Cold or Strenuous dive planning rule - ANS Use the next greater dive TIME to determine
letter group
Equilibrium as it relates to nitrogen in the body - ANS When the pressure of nitrogen is
balanced between air and your body
Haldane surfacing ratio - ANS Originally 2:1 - Updated with new research to 1.58:1
1 @COPYRIGHT 2025/2026.
,Tissue compartment half-time - ANS The time required for the compartment to absorb or
eliminate half of the pressure difference between what it started with and the ambient
pressure
M-Value of tissue - ANS The maximum allowable nitrogen (inert gas) pressure in a specific
tissue
NAUI recommendation for diving while pregnant - ANS Do not dive while pregnant
Haldane tissue compartments - ANS Haldane - 5 compartments
Modern Computers - Apx. 16 compartments
Tissue compartment - ANS Mathematical model consisting of multiple theoretical tissues and
their relative halftimes
Fast compartments - short halftimes
Slow compartments - long halftimes
Ascent rate at altitude - ANS Slower than at sea level
Extend dive times with gas by - ANS Decreased nitrogen and increased oxygen in breathing
gas
RNT - ANS Residual Nitrogen Time
Tme already spent at the repetitive dive depth (dive tables)
Procedure for missed decompression stops - ANS Remain out of the water, rest, breathe
100% oxygen, drink fluids, be monitored for signs of decompression illness, transported to a
hyperbaric facility if symptoms arise
2 @COPYRIGHT 2025/2026.
, SIT - ANS Surface Interval Time
Longer time at the surface allows for increased repeat dive times
Canadian Dive Tables published by the Defense and Civil Institute of Environmental Medicine
(DCIEM) - ANS Based on 20+ years of research pioneered by Kidd and Stubbs (1962)
Swiss Dive Tables - ANS Developed by A.A. Bühlmann at the University of Zurich - EXTENDED
TO INCLUDE ALTITUDE DIVING
If the time spent making a "precautionary stop" at 5 msw (15 fsw) causes your Total Dive Time
to exceed the Dive Time Limits, you should: - ANS Use the Maximum Dive Time as your Total
Dive Time
Aching pains an hour after a dive might be: - ANS Decompression sickness
ATA rating for most hyperbaric chambers for treating divers: - ANS 6 ATA
Haldane Tissue Half-Times (Compartments) - ANS 5, 10, 20, 40, 75 Mins
High altitude dive - ANS Any dive at greater than 1000 feet
Ideal hyperbaric chamber for dive injury - ANS Multiplace, double-lock chamber rated for
service to six atmospheres
Repetitive Dive - ANS Any dive started within 24 hours after a previous dive
NAUI recommended minimum SIT time - ANS 60 mins
3 @COPYRIGHT 2025/2026.
