SDI Scuba Certification Exam Study Guide Questions and Answers 100% Verified

SDI Scuba Certification Exam Study Guide Questions and Answers
100% Verified


1. Define SCUBA: S - self C - s s s s s s


contained
s


U- s


underwater B -
s s s


breathing A -
s s s


apparatus
s


2. List 3 important scuba diving changes that occurred in 1950s: 1) published USN dive ta
s s s s s s s s s s s s s s


bles
2) invented the personal dive computer s s s s


3) equipment manufacturers made improvements to the design and workmanship of gear
s s s s s s s s s s


3. Name 3 different devices that modern dive computers replace: 1) dive tables
s s s s s s s s s s s


2) J-valves
3) depth gauges s


4. What sets SDI apart from other training agencies?: First dive training agency to provide e
s s s s s s s s s s s s s s


ntry level scuba instruction that incorporates the use of personal dive computers --
s s s s s s s s s s s s


> more streamlined scuba course w/ more instruction time in the water
s s s s s s s s s s s


5. How much larger and closer do objects appear underwater and why?: Ob-
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jects underwater appear 25% larger and 25% closer
s s s s s s s s




As light travels through the airspace created by the mask, it bends, creating a magnifying effec
s s s s s s s s s s s s s s s


6. How much faster does sound move through water than air and why?: 4 times faster becaus
s s s s s s s s s s s s s s s


e water is about 800 times denser than air.
s s s s s s s s


7. What is the first color to be absorbed underwater?: Red (within first 25 feet)
s s s s s s s s s s s s s


8. When diving from shore, the best time to dive is when there is the least amount of ti
s s s s s s s s s s s s s s s s s


dal current.s s


tide is when there is no horizontal water movement.: Slack tide
s s s s s s s s s s


9. If you are caught in a rip current, first swim
s s to the current to get out of it before sw
s s s s s s s ss s s s s s s s s s s s s



1s/s
17

,imming towards shore.: Parallel
s s s


10. Waves are usually caused by: Wind pushing water on the surface
s s s s s s s s s s


11. T or F: Anticipate surge action to avoid contact with stationary objects: -
s s s s s s s s s s s s


True
12. What type of marine life cause most diving injuries?: Most diving injuries result from
s s s s s s s s s s s s s s


animal's defensive response to a perceived threat
s s s s s s


13. What should you do if you see a potentially dangerous animal underwater and it does
s s s s s s s s s s s s s s s


not leave the area?: Remain still and calm. Slowly leave area if necessary.
s s s s s s s s s s s s


14. List three different reasons that it is advisable to check with your local dive center befor
s s s s s s s s s s s s s s s


e conducting a dive in an area you are unfamiliar with?: 1) tidal
s s s s s s s s s s s s




2s/s
17

, conditions
2) marine life s


3) first aid for potential injuries in areas s s s s s


15. What is the absolute pressure (in atm/bar) at 20 meters (66 feet)?: 3 atm/bar
s s s s s s s s s s s s s


16. What will be the volume in a ball that is filled with 2 cubic feet/liters of air at 30 meters (
s s s s s s s s s s s s s s s s s s s s


90 feet) when it is taken to surface?: 8 cubic feet/liter (4x the volume)
s s s s s s s s s s s s s


17. How many more times dense is the air in a ballon at 4 atm/bar compared to air densi
s s s s s s s s s s s s s s s s s


ty at surface?: 4x
s s s


18. If a scuba cylinder lasts two hours at sea level, how long will it last at 20 m/66 ft?: 40
s s s s s s s s s s s s s s s s s s s s


minutes

120 min x 1/3 (vol) = 40 min
s s s s s s s


19. How often should a scuba diver equalize during descent?: At the surface before desc
s s s s s s s s s s s s s


ent and every couple of feet
s s s s s


20. What should you do if you experience discomfort in your ears upon de-
s s s s s s s s s s s s


scending?: Stop, ascend a few feet until you no longer feel discomfort, equalize again, the
s s s s s s s s s s s s s s s


n continue with descent
s s s


21. What is a reverse block?: When air cannot escape freely from an air space during asce
s s s s s s s s s s s s s s s


nt

causes pain and discomfort in the ears and sinuses
s s s s s s s s


22. What should you do if you experience a reverse block upon ascending?: -
s s s s s s s s s s s s


Stop, descend a few feet until pain subsides, wait to allow air to vent, then continue with asce
s s s s s s s s s s s s s s s s s s


nt
23. What is the most important rule in scuba diving?: Breathe continuously and never hold y
s s s s s s s s s s s s s s


our breath s


24. What is the most serious injury that a diver could suffer from if they hold their breath
s s s s s s s s s s s s s s s s s


upon ascending?: Lung over-expansion
s s s


25. Which gas component in air causes decompression sickness and narco-
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sis?: Nitrogen
s s


26. What medical problem can occur if a diver ascends much too rapidly for nitrogen to
s s s s s s s s s s s s s s s




3s/s
17