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SDI SCUBA CERTIFICATION EXAM
STUDY GUIDE WITH COR RECT
ANSWERS | 100% VERIFIED
Question 1: Define SCUBA
CORRECT ANSWER: S - self, C - contained, U -
underwater, B - breathing, A - apparatus
Question 2: List 3 important scuba diving changes that
occurred in the 1950s
CORRECT ANSWER: 1) published USN dive tables, 2)
invented the personal dive computer, 3) equipment manufacturers made improvements to the design and workmanship of gear
Question 3: Name 3 different devices that modern dive
computers replace
CORRECT ANSWER: 1) dive tables, 2) J-valves, 3)
depth gauges
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Question 4: What sets SDI apart from other training
agencies?
CORRECT ANSWER: 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
Question 5: How much larger and closer do objects
appear underwater and why?
CORRECT ANSWER: Objects underwater appear 25%
larger and 25% closer. As light travels through the airspace created by the mask, it bends, creating a magnifying effect.
Question 6: How much faster does sound move through
water than air and why?
CORRECT ANSWER: 4 times faster because water is
about 800 times denser than air.
Question 7: What is the first color to be absorbed
underwater?
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CORRECT ANSWER: Red (within first 25 feet)
Question 8: 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.
CORRECT ANSWER: Slack tide
Question 9: If you are caught in a rip current, first swim
_____ to the current to get out of it before swimming towards shore.
CORRECT ANSWER: Parallel
Question 10: Waves are usually caused by
CORRECT ANSWER: Wind pushing water on the
surface
Question 11: T or F: Anticipate surge action to avoid contact with stationary objects
CORRECT ANSWER: True
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Question 12: What type of marine life cause most diving
injuries?
CORRECT ANSWER: Most diving injuries result from
animal's defensive response to a perceived threat
Question 13: What should you do if you see a potentially
dangerous animal underwater and it does not leave the area?
CORRECT ANSWER: Remain still and calm. Slowly
leave area if necessary.
Question 14: List three different reasons that it is
advisable to check with your local dive center before conducting a dive in an area you are unfamiliar with?
CORRECT ANSWER: 1) tidal conditions, 2) marine life,
3) first aid for potential injuries in area
Question 15: What is the absolute pressure (in atm/bar) at
20 meters (66 feet)?