SDI Scuba Certification Exam Study
Guide: Questions & Answers
Define SCUBA
(Ans-
S - self
C - contained
U - underwater
B - breathing
A - apparatus
List 3 important scuba diving changes that occurred in 1950s
(Ans-
1) published USN dive tables
2) invented the personal dive computer
3) equipment manufacturers made improvements to the design and
workmanship of gear
Name 3 different devices that modern dive computers replace
(Ans-
1) dive tables
2) J-valves
3) depth gauges
What sets SDI apart from other training agencies?
(Ans- First dive training agency to provide entry level scuba instruction that
incorporates the use of personal dive computers --> more streamlined
scuba course w/ more instruction time in the water
How much larger and closer do objects appear underwater and why?
(Ans- Objects underwater appear 25% larger and 25% closer
, As light travels through the airspace created by the mask, it bends, creating
a magnifying effect.
How much faster does sound move through water than air and why?
(Ans- 4 times faster because water is about 800 times denser than air.
What is the first color to be absorbed underwater?
(Ans- Red (within first 25 feet)
When diving from shore, the best time to dive is when there is the least
amount of tidal current. _______ tide is when there is no horizontal water
movement.
(Ans- Slack tide
If you are caught in a rip current, first swim _____ to the current to get out
of it before swimming towards shore.
(Ans- Parallel
Waves are usually caused by
(Ans- Wind pushing water on the surface
T or F: Anticipate surge action to avoid contact with stationary objects
(Ans- True
What type of marine life cause most diving injuries?
(Ans- Most diving injuries result from animal's defensive response to a
perceived threat
What should you do if you see a potentially dangerous animal underwater
and it does not leave the area?
(Ans- Remain still and calm. Slowly leave area if necessary.
Guide: Questions & Answers
Define SCUBA
(Ans-
S - self
C - contained
U - underwater
B - breathing
A - apparatus
List 3 important scuba diving changes that occurred in 1950s
(Ans-
1) published USN dive tables
2) invented the personal dive computer
3) equipment manufacturers made improvements to the design and
workmanship of gear
Name 3 different devices that modern dive computers replace
(Ans-
1) dive tables
2) J-valves
3) depth gauges
What sets SDI apart from other training agencies?
(Ans- First dive training agency to provide entry level scuba instruction that
incorporates the use of personal dive computers --> more streamlined
scuba course w/ more instruction time in the water
How much larger and closer do objects appear underwater and why?
(Ans- Objects underwater appear 25% larger and 25% closer
, As light travels through the airspace created by the mask, it bends, creating
a magnifying effect.
How much faster does sound move through water than air and why?
(Ans- 4 times faster because water is about 800 times denser than air.
What is the first color to be absorbed underwater?
(Ans- Red (within first 25 feet)
When diving from shore, the best time to dive is when there is the least
amount of tidal current. _______ tide is when there is no horizontal water
movement.
(Ans- Slack tide
If you are caught in a rip current, first swim _____ to the current to get out
of it before swimming towards shore.
(Ans- Parallel
Waves are usually caused by
(Ans- Wind pushing water on the surface
T or F: Anticipate surge action to avoid contact with stationary objects
(Ans- True
What type of marine life cause most diving injuries?
(Ans- Most diving injuries result from animal's defensive response to a
perceived threat
What should you do if you see a potentially dangerous animal underwater
and it does not leave the area?
(Ans- Remain still and calm. Slowly leave area if necessary.
