PADI Open Water Diver Final – Professional Association
of Diving Instructors (PADI)
SECTION 1: DIVING EQUIPMENT
Questions 1–15
Question 1
What is the PRIMARY function of a scuba regulator?
A) To measure the amount of air remaining in the cylinder
B) To reduce high-pressure air from the cylinder to ambient pressure for
breathing
C) To inflate the buoyancy control device
D) To provide a secure attachment point for the alternate air source
Correct Answer: B
Rationale: The scuba regulator reduces high-pressure air from the cylinder to
ambient (surrounding) pressure so you can breathe comfortably at any depth.
Option A describes the function of the submersible pressure gauge (SPG). Option
C describes the BCD low-pressure inflator. Option D describes a retainer clip, not a
regulator function.
Question 2
Before every dive, you and your buddy should perform a predive safety check.
What does each letter of the "BWRAF" mnemonic stand for?
A) Buoyancy, Weights, Releases, Air, Final OK
B) BCD, Weights, Regulator, Air, Fins
C) Buoyancy, Water, Releases, Alerts, Final OK
D) BCD, Watch, Releases, Air, Flotation
Correct Answer: A
, Rationale: BWRAF = BCD (check inflator and deflator), Weights (verify weight
system is secure and releasable), Releases (check all buckles and releases), Air
(confirm air is on, sufficient, and breathable), Final OK (complete equipment
check and plan review). All other options include incorrect terms not part of the
official BWRAF check.
Question 3
Your alternate air source (octopus regulator) should be stored:
A) In your BCD pocket for easy access
B) Secured within the triangle formed by your chin and the lower corners of your
ribcage
C) Clipped to the back of your cylinder valve
D) Allowed to hang freely behind you to avoid tangling
Correct Answer: B
Rationale: The alternate air source must be kept in the "golden triangle"—the
area between your chin and the lower corners of your ribcage—so both you and
your buddy can locate and access it quickly in an emergency. Pockets, cylinder
valves, and trailing positions all make emergency access difficult or impossible.
Question 4
A submersible pressure gauge (SPG) shows you:
A) Your current depth below the surface
B) The amount of air pressure remaining in your cylinder
C) Your total bottom time for the dive
D) Your rate of ascent toward the surface
Correct Answer: B
Rationale: The SPG displays the remaining air pressure in your cylinder,
typically measured in bar or PSI. Your current depth is shown by a depth gauge or
dive computer. Bottom time is tracked by a dive watch or dive computer. Ascent
rate is monitored via a dive computer or by observing bubble streams.
,Question 5
The buoyancy control device (BCD) serves which PRIMARY function during a dive?
A) To hold and secure your scuba cylinder on your back
B) To allow you to achieve and maintain neutral buoyancy underwater
C) To provide emergency breathing gas if your main regulator fails
D) To measure and display your current depth
Correct Answer: B
Rationale: The BCD's primary function is buoyancy control—adding air to
become more buoyant and releasing air to become less buoyant, allowing the
diver to achieve neutral buoyancy underwater. While the BCD does help secure
the cylinder (A), its primary purpose is buoyancy management.
Question 6
Which of the following is the MOST important rule in scuba diving?
A) Always dive with a buddy
B) Breathe continuously and never hold your breath
C) Never dive deeper than 18 meters
D) Always wear a wetsuit
Correct Answer: B
Rationale: Holding your breath during ascent causes the air in your lungs to
expand as water pressure decreases, which can lead to life-threatening lung over-
expansion injuries (pulmonary barotrauma). This is the single most important rule
in scuba diving. While diving with a buddy is important for safety, breath-holding
is the rule that directly prevents fatal injury.
Question 7
Which piece of equipment converts high-pressure air from the cylinder to
ambient pressure?
, A) The BCD
B) The submersible pressure gauge (SPG)
C) The regulator
D) The snorkel
Correct Answer: C
Rationale: The regulator reduces high-pressure tank air to the pressure of the
surrounding water (ambient pressure) so you can breathe it comfortably at any
depth. The BCD manages buoyancy, the SPG measures remaining air pressure,
and the snorkel is used for surface breathing.
Question 8
A diver's cylinder contains 200 bar of compressed air at the surface. If the diver
descends to 20 meters (3 atmospheres absolute), the available air volume for
breathing will:
A) Remain the same
B) Decrease to one-third
C) Increase to three times
D) Decrease to one-half
Correct Answer: B
Rationale: According to Boyle's Law, at 20 meters (3 ata), the pressure is
three times that of the surface. The volume of gas decreases proportionally—the
air the diver breathes is compressed, meaning each breath consumes more air
from the cylinder. The cylinder pressure reading remains 200 bar, but the gas is
more dense and will be consumed faster.
Question 9
What is the purpose of the low-pressure inflator hose on a BCD?
A) To connect the BCD to the cylinder's high-pressure port
B) To add air to the BCD from the cylinder
of Diving Instructors (PADI)
SECTION 1: DIVING EQUIPMENT
Questions 1–15
Question 1
What is the PRIMARY function of a scuba regulator?
A) To measure the amount of air remaining in the cylinder
B) To reduce high-pressure air from the cylinder to ambient pressure for
breathing
C) To inflate the buoyancy control device
D) To provide a secure attachment point for the alternate air source
Correct Answer: B
Rationale: The scuba regulator reduces high-pressure air from the cylinder to
ambient (surrounding) pressure so you can breathe comfortably at any depth.
Option A describes the function of the submersible pressure gauge (SPG). Option
C describes the BCD low-pressure inflator. Option D describes a retainer clip, not a
regulator function.
Question 2
Before every dive, you and your buddy should perform a predive safety check.
What does each letter of the "BWRAF" mnemonic stand for?
A) Buoyancy, Weights, Releases, Air, Final OK
B) BCD, Weights, Regulator, Air, Fins
C) Buoyancy, Water, Releases, Alerts, Final OK
D) BCD, Watch, Releases, Air, Flotation
Correct Answer: A
, Rationale: BWRAF = BCD (check inflator and deflator), Weights (verify weight
system is secure and releasable), Releases (check all buckles and releases), Air
(confirm air is on, sufficient, and breathable), Final OK (complete equipment
check and plan review). All other options include incorrect terms not part of the
official BWRAF check.
Question 3
Your alternate air source (octopus regulator) should be stored:
A) In your BCD pocket for easy access
B) Secured within the triangle formed by your chin and the lower corners of your
ribcage
C) Clipped to the back of your cylinder valve
D) Allowed to hang freely behind you to avoid tangling
Correct Answer: B
Rationale: The alternate air source must be kept in the "golden triangle"—the
area between your chin and the lower corners of your ribcage—so both you and
your buddy can locate and access it quickly in an emergency. Pockets, cylinder
valves, and trailing positions all make emergency access difficult or impossible.
Question 4
A submersible pressure gauge (SPG) shows you:
A) Your current depth below the surface
B) The amount of air pressure remaining in your cylinder
C) Your total bottom time for the dive
D) Your rate of ascent toward the surface
Correct Answer: B
Rationale: The SPG displays the remaining air pressure in your cylinder,
typically measured in bar or PSI. Your current depth is shown by a depth gauge or
dive computer. Bottom time is tracked by a dive watch or dive computer. Ascent
rate is monitored via a dive computer or by observing bubble streams.
,Question 5
The buoyancy control device (BCD) serves which PRIMARY function during a dive?
A) To hold and secure your scuba cylinder on your back
B) To allow you to achieve and maintain neutral buoyancy underwater
C) To provide emergency breathing gas if your main regulator fails
D) To measure and display your current depth
Correct Answer: B
Rationale: The BCD's primary function is buoyancy control—adding air to
become more buoyant and releasing air to become less buoyant, allowing the
diver to achieve neutral buoyancy underwater. While the BCD does help secure
the cylinder (A), its primary purpose is buoyancy management.
Question 6
Which of the following is the MOST important rule in scuba diving?
A) Always dive with a buddy
B) Breathe continuously and never hold your breath
C) Never dive deeper than 18 meters
D) Always wear a wetsuit
Correct Answer: B
Rationale: Holding your breath during ascent causes the air in your lungs to
expand as water pressure decreases, which can lead to life-threatening lung over-
expansion injuries (pulmonary barotrauma). This is the single most important rule
in scuba diving. While diving with a buddy is important for safety, breath-holding
is the rule that directly prevents fatal injury.
Question 7
Which piece of equipment converts high-pressure air from the cylinder to
ambient pressure?
, A) The BCD
B) The submersible pressure gauge (SPG)
C) The regulator
D) The snorkel
Correct Answer: C
Rationale: The regulator reduces high-pressure tank air to the pressure of the
surrounding water (ambient pressure) so you can breathe it comfortably at any
depth. The BCD manages buoyancy, the SPG measures remaining air pressure,
and the snorkel is used for surface breathing.
Question 8
A diver's cylinder contains 200 bar of compressed air at the surface. If the diver
descends to 20 meters (3 atmospheres absolute), the available air volume for
breathing will:
A) Remain the same
B) Decrease to one-third
C) Increase to three times
D) Decrease to one-half
Correct Answer: B
Rationale: According to Boyle's Law, at 20 meters (3 ata), the pressure is
three times that of the surface. The volume of gas decreases proportionally—the
air the diver breathes is compressed, meaning each breath consumes more air
from the cylinder. The cylinder pressure reading remains 200 bar, but the gas is
more dense and will be consumed faster.
Question 9
What is the purpose of the low-pressure inflator hose on a BCD?
A) To connect the BCD to the cylinder's high-pressure port
B) To add air to the BCD from the cylinder
