SDI SCUBA CERTIFICATION EXAM 2026 STUDY
GUIDE WITH CORRECT ANSWERS 100%
VERIFIED
◉ 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
◉ Name 3 different devices that modern dive computers replace.
Answer: 1) dive tables
2) J-valves
3) depth gauges
◉ 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
◉ 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 effect.
◉ 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.
◉ What is the first color to be absorbed underwater?. Answer: 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.. Answer: Slack tide
◉ If you are caught in a rip current, first swim _____ to the current to
get out of it before swimming towards shore.. Answer: Parallel
◉ Waves are usually caused by. Answer: Wind pushing water on the
surface
◉ T or F: Anticipate surge action to avoid contact with stationary
objects. Answer: True
, ◉ What type of marine life cause most diving injuries?. Answer:
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?. Answer: Remain still and
calm. Slowly leave area if necessary.
◉ 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
◉ What is the absolute pressure (in atm/bar) at 20 meters (66
feet)?. Answer: 3 atm/bar
◉ 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)
◉ How many more times dense is the air in a ballon at 4 atm/bar
compared to air density at surface?. Answer: 4x
GUIDE WITH CORRECT ANSWERS 100%
VERIFIED
◉ 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
◉ Name 3 different devices that modern dive computers replace.
Answer: 1) dive tables
2) J-valves
3) depth gauges
◉ 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
◉ 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 effect.
◉ 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.
◉ What is the first color to be absorbed underwater?. Answer: 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.. Answer: Slack tide
◉ If you are caught in a rip current, first swim _____ to the current to
get out of it before swimming towards shore.. Answer: Parallel
◉ Waves are usually caused by. Answer: Wind pushing water on the
surface
◉ T or F: Anticipate surge action to avoid contact with stationary
objects. Answer: True
, ◉ What type of marine life cause most diving injuries?. Answer:
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?. Answer: Remain still and
calm. Slowly leave area if necessary.
◉ 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
◉ What is the absolute pressure (in atm/bar) at 20 meters (66
feet)?. Answer: 3 atm/bar
◉ 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)
◉ How many more times dense is the air in a ballon at 4 atm/bar
compared to air density at surface?. Answer: 4x
