Divemaster Certification Exam Practice
Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1.Which gas law best explains why a diver's lungs expand during ascent if
they hold their breath?
A. Dalton's Law
B. Boyle's Law
C. Henry's Law
D. Charles's Law
Rationale: Boyle's Law states that gas volume is inversely proportional to
pressure at a constant temperature. As pressure decreases during ascent,
gas expands, making continuous breathing essential to prevent lung
overexpansion injuries.
2. A Divemaster's primary responsibility during guided dives is to:
A. Teach new diving skills independently
B. Certify divers
C. Supervise certified divers while promoting safety
D. Conduct instructor-level training
Rationale: Divemasters supervise diving activities, lead certified divers, and
assist instructors within the limits of their professional rating. They may
not independently certify divers.
3. Which condition is most directly caused by dissolved nitrogen forming
bubbles during ascent?
, A. Oxygen toxicity
B. Carbon monoxide poisoning
C. Decompression sickness
D. Hypercapnia
Rationale: Decompression sickness results from inert gas bubbles forming
in body tissues and bloodstream when ascent is too rapid or
decompression obligations are ignored.
4. When planning a dive, the most conservative diver in the group should
determine:
A. Maximum visibility
B. Swimming speed
C. Depth and bottom time
D. Equipment brand selection
Rationale: Planning according to the least experienced or most
conservative diver increases overall group safety and reduces risk.
5. Which equipment component is designed to provide an emergency
alternate source of breathing gas?
A. SPG
B. Alternate air source (octopus)
C. Compass
D. Dive computer
Rationale: The alternate air source is intended for emergency gas sharing
when a diver experiences an out-of-air situation.
6. Which statement best describes nitrogen narcosis?
A. It permanently damages the nervous system.
B. It only occurs deeper than 100 m.
C. It temporarily impairs judgment at increased pressure.
D. It results from breathing excessive oxygen.
Rationale: Nitrogen narcosis is a reversible impairment of cognitive
function caused by increased partial pressure of nitrogen at depth.
, 7. Before leading a dive, a Divemaster should always:
A. Select the deepest route available.
B. Allow divers to determine their own emergency procedures.
C. Conduct a thorough dive briefing and risk assessment.
D. Skip equipment checks if divers are experienced.
Rationale: Effective dive briefings and hazard assessments are essential
professional responsibilities that improve safety and communication.
8. Which emergency signal is commonly used by banging a tank
underwater?
A. End the dive immediately.
B. Surface immediately.
C. Get the attention of nearby divers.
D. Begin decompression stops.
Rationale: Striking a tank is a commonly accepted method of attracting
divers' attention during underwater emergencies or important
communications.
9. What is the recommended ascent rate according to modern
recreational diving practices?
A. 30 m/min
B. 24 m/min
C. No faster than approximately 9–10 m/min
D. 3 m/min
Rationale: A slow ascent reduces the likelihood of decompression sickness
and allows safe elimination of dissolved inert gases.
10. Why is maintaining neutral buoyancy important for
Divemasters?
A. It reduces air pressure.
B. It prevents nitrogen absorption.
C. It minimizes environmental damage and improves diver control.
D. It increases breathing gas supply.
Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1.Which gas law best explains why a diver's lungs expand during ascent if
they hold their breath?
A. Dalton's Law
B. Boyle's Law
C. Henry's Law
D. Charles's Law
Rationale: Boyle's Law states that gas volume is inversely proportional to
pressure at a constant temperature. As pressure decreases during ascent,
gas expands, making continuous breathing essential to prevent lung
overexpansion injuries.
2. A Divemaster's primary responsibility during guided dives is to:
A. Teach new diving skills independently
B. Certify divers
C. Supervise certified divers while promoting safety
D. Conduct instructor-level training
Rationale: Divemasters supervise diving activities, lead certified divers, and
assist instructors within the limits of their professional rating. They may
not independently certify divers.
3. Which condition is most directly caused by dissolved nitrogen forming
bubbles during ascent?
, A. Oxygen toxicity
B. Carbon monoxide poisoning
C. Decompression sickness
D. Hypercapnia
Rationale: Decompression sickness results from inert gas bubbles forming
in body tissues and bloodstream when ascent is too rapid or
decompression obligations are ignored.
4. When planning a dive, the most conservative diver in the group should
determine:
A. Maximum visibility
B. Swimming speed
C. Depth and bottom time
D. Equipment brand selection
Rationale: Planning according to the least experienced or most
conservative diver increases overall group safety and reduces risk.
5. Which equipment component is designed to provide an emergency
alternate source of breathing gas?
A. SPG
B. Alternate air source (octopus)
C. Compass
D. Dive computer
Rationale: The alternate air source is intended for emergency gas sharing
when a diver experiences an out-of-air situation.
6. Which statement best describes nitrogen narcosis?
A. It permanently damages the nervous system.
B. It only occurs deeper than 100 m.
C. It temporarily impairs judgment at increased pressure.
D. It results from breathing excessive oxygen.
Rationale: Nitrogen narcosis is a reversible impairment of cognitive
function caused by increased partial pressure of nitrogen at depth.
, 7. Before leading a dive, a Divemaster should always:
A. Select the deepest route available.
B. Allow divers to determine their own emergency procedures.
C. Conduct a thorough dive briefing and risk assessment.
D. Skip equipment checks if divers are experienced.
Rationale: Effective dive briefings and hazard assessments are essential
professional responsibilities that improve safety and communication.
8. Which emergency signal is commonly used by banging a tank
underwater?
A. End the dive immediately.
B. Surface immediately.
C. Get the attention of nearby divers.
D. Begin decompression stops.
Rationale: Striking a tank is a commonly accepted method of attracting
divers' attention during underwater emergencies or important
communications.
9. What is the recommended ascent rate according to modern
recreational diving practices?
A. 30 m/min
B. 24 m/min
C. No faster than approximately 9–10 m/min
D. 3 m/min
Rationale: A slow ascent reduces the likelihood of decompression sickness
and allows safe elimination of dissolved inert gases.
10. Why is maintaining neutral buoyancy important for
Divemasters?
A. It reduces air pressure.
B. It prevents nitrogen absorption.
C. It minimizes environmental damage and improves diver control.
D. It increases breathing gas supply.
