Page | 1
PADI OPEN WATER Practice Exam
Questions and Answers Latest Versions
2025 Graded A+
What are 4 common sizes and 2 materials for scuba cylinders? -
correct answer -8, 10, 12, 15 liters
aluminum and steel
What 5 common markings do you commonly find on the neck of a
scuba cylinder? - correct answer -1) type of material cylinder is
made of
2) max pressure permitted in cylinder
3) serial number
4) dates of pressure tests
5) manufacturer symbol
What are 2 basic types of cylinder valves? - correct answer -K-
valve: simple on and off
J-valve: built in mechanism that signals when you run low on air
What's the difference between a DIN valve and a Yoke valve? -
correct answer -DIN: screw the regulator into the valve
Yoke: most common, attach regulator via Yoke
, Page | 2
What is the purpose of a burst disc? - correct answer -relieve the
cylinder over pressurization which can happen from overfilling the
cylinder or excess heat
How do you turn a cylinder valve on and off? - correct answer -
Open slowly until it stops turning
Close it all the way gently
What's the best way to keep water out of a scuba cylinder? -
correct answer -never allow it to be completely empty
Why do you need scuba cylinder visual inspections and pressure
tests? - correct answer -overfilling can lead to metal fatigue and
shorten the life of the cylinder
to avoid corrosion
What does a regulator do? - correct answer -- makes it possible to
use the air to your cylinder
- reduces scuba cylinder's high pressure air to match the
surrounding water pressure
, Page | 3
When looking at a regulator, which are the following parts:
first stage - correct answer -first stage: attach to scuba cylinder
valve
second stage: has a mouthpiece
What's the most important feature for consideration when
purchasing a regulator? - correct answer -ease of breathing
How do you rinse a regulator after use? - correct answer -soak it,
while attached to your scuba cylinder
then rinse with running water
What 3 points do you need to keep in mind when rinsing your
regulator? - correct answer -1)put the first stage dust cover firmly
in place to keep H2o out of first stage
2) Do not use high pressure water to rinse
3) Don't press the purge button while rinsing or soaking, bc it
opens the second stage inlet valve
What is a SPG? - correct answer -Submersible Pressure Gauge
Why do divers need a submersible pressure gauge? - correct
PADI OPEN WATER Practice Exam
Questions and Answers Latest Versions
2025 Graded A+
What are 4 common sizes and 2 materials for scuba cylinders? -
correct answer -8, 10, 12, 15 liters
aluminum and steel
What 5 common markings do you commonly find on the neck of a
scuba cylinder? - correct answer -1) type of material cylinder is
made of
2) max pressure permitted in cylinder
3) serial number
4) dates of pressure tests
5) manufacturer symbol
What are 2 basic types of cylinder valves? - correct answer -K-
valve: simple on and off
J-valve: built in mechanism that signals when you run low on air
What's the difference between a DIN valve and a Yoke valve? -
correct answer -DIN: screw the regulator into the valve
Yoke: most common, attach regulator via Yoke
, Page | 2
What is the purpose of a burst disc? - correct answer -relieve the
cylinder over pressurization which can happen from overfilling the
cylinder or excess heat
How do you turn a cylinder valve on and off? - correct answer -
Open slowly until it stops turning
Close it all the way gently
What's the best way to keep water out of a scuba cylinder? -
correct answer -never allow it to be completely empty
Why do you need scuba cylinder visual inspections and pressure
tests? - correct answer -overfilling can lead to metal fatigue and
shorten the life of the cylinder
to avoid corrosion
What does a regulator do? - correct answer -- makes it possible to
use the air to your cylinder
- reduces scuba cylinder's high pressure air to match the
surrounding water pressure
, Page | 3
When looking at a regulator, which are the following parts:
first stage - correct answer -first stage: attach to scuba cylinder
valve
second stage: has a mouthpiece
What's the most important feature for consideration when
purchasing a regulator? - correct answer -ease of breathing
How do you rinse a regulator after use? - correct answer -soak it,
while attached to your scuba cylinder
then rinse with running water
What 3 points do you need to keep in mind when rinsing your
regulator? - correct answer -1)put the first stage dust cover firmly
in place to keep H2o out of first stage
2) Do not use high pressure water to rinse
3) Don't press the purge button while rinsing or soaking, bc it
opens the second stage inlet valve
What is a SPG? - correct answer -Submersible Pressure Gauge
Why do divers need a submersible pressure gauge? - correct
