SDI Scuba Certification Exam Study Guide
With Correct Answers, 100% Guarantee Pass
1. Define SCUBA
Answer: S - self C -
contained
U - underwater
B - breathing
A - apparatus
2. List 3 important scuba diving changes that occurred in 1950s
Answer: 1) published USN dive tables
2) invented the personal dive computer
3) equipment manufacturers made improvements to the design and workmanship of gear
3. Name 3 different devices that modern dive computers replace
Answer: 1) dive tables
2) J-valves
3) depth gauges
,4. What sets SDI apart from other training agencies?
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
5. How much larger and closer do objects appear underwater and why?
Answer: Objects underwater appear 25% larger and 25% closer
As light travels through the airspace created by the mask, it bends, creating a magnifying ettect.
6. How much faster does sound move through water than air and why?
Answer: 4 times faster because water is about 800 times denser than air.
7. What is the first color to be absorbed underwater?
Answer: Red (within first 25 feet)
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.
Answer: Slack tide
9. If you are caught in a rip current, first swim to the current to get out of
it before swimming towards shore.
Answer: Parallel
10. Waves are usually caused by
, Answer: Wind pushing water on the surface
11. T or F Anticipate surge action to avoid contact with stationary objects
Answer: True
12. What type of marine life cause most diving injuries?
Answer: Most diving injuries result from animal's defensive response to a perceived threat
13. What should you do if you see a potentially dangerous animal underwater and
it does not leave the area?
Answer: Remain still and calm. Slowly leave area if necessary.
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?
Answer: 1) tidal conditions
2) marine life
3) first aid for potential injuries in area
15. What is the absolute pressure (in atm/bar) at 20 meters (66 feet)?
Answer: 3 atm/bar
16. What will be the volume in a ball that is filled with 2 cubic feet/liters of air at 30
meters (90 feet) when it is taken to surface?
Answer: 8 cubic feet/liter (4x the volume)
17. How many more times dense is the air in a ballon at 4 atm/bar compared to
With Correct Answers, 100% Guarantee Pass
1. Define SCUBA
Answer: S - self C -
contained
U - underwater
B - breathing
A - apparatus
2. List 3 important scuba diving changes that occurred in 1950s
Answer: 1) published USN dive tables
2) invented the personal dive computer
3) equipment manufacturers made improvements to the design and workmanship of gear
3. Name 3 different devices that modern dive computers replace
Answer: 1) dive tables
2) J-valves
3) depth gauges
,4. What sets SDI apart from other training agencies?
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
5. How much larger and closer do objects appear underwater and why?
Answer: Objects underwater appear 25% larger and 25% closer
As light travels through the airspace created by the mask, it bends, creating a magnifying ettect.
6. How much faster does sound move through water than air and why?
Answer: 4 times faster because water is about 800 times denser than air.
7. What is the first color to be absorbed underwater?
Answer: Red (within first 25 feet)
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.
Answer: Slack tide
9. If you are caught in a rip current, first swim to the current to get out of
it before swimming towards shore.
Answer: Parallel
10. Waves are usually caused by
, Answer: Wind pushing water on the surface
11. T or F Anticipate surge action to avoid contact with stationary objects
Answer: True
12. What type of marine life cause most diving injuries?
Answer: Most diving injuries result from animal's defensive response to a perceived threat
13. What should you do if you see a potentially dangerous animal underwater and
it does not leave the area?
Answer: Remain still and calm. Slowly leave area if necessary.
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?
Answer: 1) tidal conditions
2) marine life
3) first aid for potential injuries in area
15. What is the absolute pressure (in atm/bar) at 20 meters (66 feet)?
Answer: 3 atm/bar
16. What will be the volume in a ball that is filled with 2 cubic feet/liters of air at 30
meters (90 feet) when it is taken to surface?
Answer: 8 cubic feet/liter (4x the volume)
17. How many more times dense is the air in a ballon at 4 atm/bar compared to
