SDI Scuba Certification Exam Study Guide (2025/2026) ACTUAL EXAM
SDI Scuba Certification Exam Study Guide
COMPREHENSIVE QUESTIONS AND VERIFIED ACCURATE SOLUTION
Study online at https://quizlet.com/_528o57
(DETAILED & ELABORATED) |GET IT 100% ACCURATE!! 2025 TEST!!
1. Define SCUBA S - self
C - contained
U - underwater
B - breathing
A - apparatus
2. List 3 impor- 1) published USN dive tables
tant scuba diving 2) invented the personal dive computer
changes that oc- 3) equipment manufacturers made improvements to the design and workmanship
curred in 1950s of gear
3. Name 3 different 1) dive tables
devices that mod- 2) J-valves
ern dive comput- 3) depth gauges
ers replace
4. What sets SDI First dive training agency to provide entry level scuba instruction that incorporates
apart from oth- the use of personal dive computers --> more streamlined scuba course w/ more
er training agen- instruction time in the water
cies?
5. How much larg- Objects underwater appear 25% larger and 25% closer
er and closer
do objects ap- As light travels through the airspace created by the mask, it bends, creating a
pear underwater magnifying effect.
and why?
6. How much faster 4 times faster because water is about 800 times denser than air.
does sound move
through water
than air and why?
7. Red (within first 25 feet)
, SDI Scuba Certification Exam Study Guide
Study online at https://quizlet.com/_528o57
What is the first
color to be ab-
sorbed underwa-
ter?
8. When diving Slack tide
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.
9. If you are caught Parallel
in a rip current,
first swim _____
to the current
to get out of it
before swimming
towards shore.
10. Waves are usually Wind pushing water on the surface
caused by
11. T or F: Antic- True
ipate surge ac-
tion to avoid con-
tact with station-
ary objects
, SDI Scuba Certification Exam Study Guide
Study online at https://quizlet.com/_528o57
12. What type of ma- Most diving injuries result from animal's defensive response to a perceived threat
rine life cause
most diving in-
juries?
13. What should you Remain still and calm. Slowly leave area if necessary.
do if you see a po-
tentially danger-
ous animal un-
derwater and it
does not leave
the area?
14. List three differ- 1) tidal conditions
ent reasons that 2) marine life
it is advisable to 3) first aid for potential injuries in area
check with your
local dive center
before conduct-
ing a dive in an
area you are un-
familiar with?
15. What is the ab- 3 atm/bar
solute pressure
(in atm/bar) at 20
meters (66 feet)?
16. What will be the 8 cubic feet/liter (4x the volume)
volume in a ball
that is filled with
2 cubic feet/liters
of air at 30
SDI Scuba Certification Exam Study Guide
COMPREHENSIVE QUESTIONS AND VERIFIED ACCURATE SOLUTION
Study online at https://quizlet.com/_528o57
(DETAILED & ELABORATED) |GET IT 100% ACCURATE!! 2025 TEST!!
1. Define SCUBA S - self
C - contained
U - underwater
B - breathing
A - apparatus
2. List 3 impor- 1) published USN dive tables
tant scuba diving 2) invented the personal dive computer
changes that oc- 3) equipment manufacturers made improvements to the design and workmanship
curred in 1950s of gear
3. Name 3 different 1) dive tables
devices that mod- 2) J-valves
ern dive comput- 3) depth gauges
ers replace
4. What sets SDI First dive training agency to provide entry level scuba instruction that incorporates
apart from oth- the use of personal dive computers --> more streamlined scuba course w/ more
er training agen- instruction time in the water
cies?
5. How much larg- Objects underwater appear 25% larger and 25% closer
er and closer
do objects ap- As light travels through the airspace created by the mask, it bends, creating a
pear underwater magnifying effect.
and why?
6. How much faster 4 times faster because water is about 800 times denser than air.
does sound move
through water
than air and why?
7. Red (within first 25 feet)
, SDI Scuba Certification Exam Study Guide
Study online at https://quizlet.com/_528o57
What is the first
color to be ab-
sorbed underwa-
ter?
8. When diving Slack tide
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.
9. If you are caught Parallel
in a rip current,
first swim _____
to the current
to get out of it
before swimming
towards shore.
10. Waves are usually Wind pushing water on the surface
caused by
11. T or F: Antic- True
ipate surge ac-
tion to avoid con-
tact with station-
ary objects
, SDI Scuba Certification Exam Study Guide
Study online at https://quizlet.com/_528o57
12. What type of ma- Most diving injuries result from animal's defensive response to a perceived threat
rine life cause
most diving in-
juries?
13. What should you Remain still and calm. Slowly leave area if necessary.
do if you see a po-
tentially danger-
ous animal un-
derwater and it
does not leave
the area?
14. List three differ- 1) tidal conditions
ent reasons that 2) marine life
it is advisable to 3) first aid for potential injuries in area
check with your
local dive center
before conduct-
ing a dive in an
area you are un-
familiar with?
15. What is the ab- 3 atm/bar
solute pressure
(in atm/bar) at 20
meters (66 feet)?
16. What will be the 8 cubic feet/liter (4x the volume)
volume in a ball
that is filled with
2 cubic feet/liters
of air at 30
