NAUI INSTRUCTOR FINAL EXAM QUESTIONS WITH
ANSWERS 2025/2026 GRADED A+
Pilotage - Location is confirmed with visual references
Reciprocal Course - An outbound course in a straight line with the return in the opposite
direction along the same line
First step in searching for an object under water - Define the search area
Two types of lift bags - Open bottom & Pillow
Where tidal currents are significant, diving from shore should generally be conducted at
or near high or low tide because: - There is a little tidal current near slack tide
Trimix - 2 inert gasses & oxygen
Wavelength - Distance from Crest to Crest of waves
Cause of tides - Gravitational pull of the moon
3 Tide cycles - Diurnal - 1 high 1 low per day
Semidiurnal - 2 high 2 low of equal sizes per day
Mixed - 2 high 2 low of differing sizes per day
Current parralell to the beach - Longshore Current
Primary cause of offshore currents - Wind
The horizontal boundary between waters of different salinity - Halocline
Most common plants in the ocean - Phytoplankton
Most common toxic poisoning in ocean fish - Ciguatera
Waves caused by the wind increase in size with the wind velocity, duration, and: - Fetch
Because of the Coriolis force, major ocean currents tend to flow: - Clockwise in the
Northern Hemisphere, counterclockwise in the Southern Hemisphere
The intertidal area in which plant and animals are adapted to withstand water loss,
temperature extremes, and strong water movement is termed the: - Littoral zone
When approaching the shore, large swells over a moderately steep bottom slope tend to
cause: - Plunging breakers
, Apx number of high tides per 24 hr day - 2
The seasonal breakdown of the thermocline in a fresh water lake is termed a/an: -
Turnover
Rip current flow - Perpendicular away from the shore
Red tide - Result of a plankton bloom
Percentage of all animal species that are invertebrates - 97%
Strongest areas for river currents - Surface, in the middle, along outside edges in bends
Epilimnion - Sun-warmed waters of lakes and quarries form an upper layer of water
during the summer
What causes higher than normal spring tides - When the solar tide reinforces and
amplifies the lunar tide
Beaufort Scale - Scale for measuring wind force/speed
When waves move into shallow water: - The wave velocity decreases and the
wavelength decreases
Slack tide - The period of change in a tidal current from a flood tide to an ebb tide (or an
ebb tide to a flood tide)
The terms "set" and "drift" refer to a current's: - Direction and velocity
Modern Cylinders - Steel or Aluminum
Internal valve types for first stages - Diaphragm & Pistol
Most common SPG - Sealed Bourdon Tube
Two most common computer models - Tissue & Table based
Two Stage regulator - Reg reduced cylinder pressure to ambient pressure in two steps
Purpose of a Hydrostatic test - To determine permanent expansion of a cylinder
Modern regulator performance is defined in terms of - Max respiratory work level
Alpha flag represents - A vessel restricted in its ability to maneuver
Which of the following is not part of the cylinder valve? - Diaphragm
ANSWERS 2025/2026 GRADED A+
Pilotage - Location is confirmed with visual references
Reciprocal Course - An outbound course in a straight line with the return in the opposite
direction along the same line
First step in searching for an object under water - Define the search area
Two types of lift bags - Open bottom & Pillow
Where tidal currents are significant, diving from shore should generally be conducted at
or near high or low tide because: - There is a little tidal current near slack tide
Trimix - 2 inert gasses & oxygen
Wavelength - Distance from Crest to Crest of waves
Cause of tides - Gravitational pull of the moon
3 Tide cycles - Diurnal - 1 high 1 low per day
Semidiurnal - 2 high 2 low of equal sizes per day
Mixed - 2 high 2 low of differing sizes per day
Current parralell to the beach - Longshore Current
Primary cause of offshore currents - Wind
The horizontal boundary between waters of different salinity - Halocline
Most common plants in the ocean - Phytoplankton
Most common toxic poisoning in ocean fish - Ciguatera
Waves caused by the wind increase in size with the wind velocity, duration, and: - Fetch
Because of the Coriolis force, major ocean currents tend to flow: - Clockwise in the
Northern Hemisphere, counterclockwise in the Southern Hemisphere
The intertidal area in which plant and animals are adapted to withstand water loss,
temperature extremes, and strong water movement is termed the: - Littoral zone
When approaching the shore, large swells over a moderately steep bottom slope tend to
cause: - Plunging breakers
, Apx number of high tides per 24 hr day - 2
The seasonal breakdown of the thermocline in a fresh water lake is termed a/an: -
Turnover
Rip current flow - Perpendicular away from the shore
Red tide - Result of a plankton bloom
Percentage of all animal species that are invertebrates - 97%
Strongest areas for river currents - Surface, in the middle, along outside edges in bends
Epilimnion - Sun-warmed waters of lakes and quarries form an upper layer of water
during the summer
What causes higher than normal spring tides - When the solar tide reinforces and
amplifies the lunar tide
Beaufort Scale - Scale for measuring wind force/speed
When waves move into shallow water: - The wave velocity decreases and the
wavelength decreases
Slack tide - The period of change in a tidal current from a flood tide to an ebb tide (or an
ebb tide to a flood tide)
The terms "set" and "drift" refer to a current's: - Direction and velocity
Modern Cylinders - Steel or Aluminum
Internal valve types for first stages - Diaphragm & Pistol
Most common SPG - Sealed Bourdon Tube
Two most common computer models - Tissue & Table based
Two Stage regulator - Reg reduced cylinder pressure to ambient pressure in two steps
Purpose of a Hydrostatic test - To determine permanent expansion of a cylinder
Modern regulator performance is defined in terms of - Max respiratory work level
Alpha flag represents - A vessel restricted in its ability to maneuver
Which of the following is not part of the cylinder valve? - Diaphragm
