DIVEMASTER FINAL EXAM A
QUESTIONS AND ANSWERS 2026
1. What is the partial pressure of oxygen (PO2) in a nitrox blend containing 36% oxygen at a
depth of 28 meters in seawater?
A. 1.37 ata
B. 1.01 ata
C. 1.44 ata
D. 0.98 ata
Answer: A
Conceptual Explanation: Depth of 28m equals 3.8 ata (2.8 + 1). PO2 = 3.8 * 0.36 = 1.368,
rounded to 1.37 ata.
2. An object weighing 450 kg displaces 300 liters of seawater. How much additional seawater
must it displace to achieve neutral buoyancy?
A. 142 liters
B. 150 liters
C. 137 liters
D. 124 liters
,Answer: C
Conceptual Explanation: The object weighs 450 kg. To be neutrally buoyant in seawater
(1.03 kg/l), it must displace .03 = 436.9 liters. It currently displaces 300, so it needs
136.9 (approx 137) more.
3. Which gas law states that at a constant temperature, the volume of a gas is inversely
proportional to the pressure?
A. Dalton’s Law
B. Charles’s Law
C. Henry’s Law
D. Boyle’s Law
Answer: D
Conceptual Explanation: Boyle’s Law describes the relationship between pressure and
volume (P1V1=P2V2).
4. If a diver consumes 20 bar of air in 10 minutes at a depth of 10 meters, how much air will
they consume in 10 minutes at 30 meters, assuming the same rate of exertion?
A. 30 bar
B. 60 bar
C. 50 bar
D. 40 bar
, Answer: D
Conceptual Explanation: At 10m (2 ata), consumption is 20 bar/10 min (10 bar/ata). At
30m (4 ata), consumption is 10 bar * 4 ata = 40 bar/10 min.
5. How much faster does sound travel in water compared to air?
A. 2 times faster
B. 4 times faster
C. 10 times faster
D. Sound travels slower in water
Answer: B
Conceptual Explanation: Sound travels approximately 4 times faster in water than in air
because water is denser and less compressible.
6. Which color of the spectrum is absorbed first as a diver descends?
A. Blue
B. Red
C. Yellow
D. Green
Answer: B
QUESTIONS AND ANSWERS 2026
1. What is the partial pressure of oxygen (PO2) in a nitrox blend containing 36% oxygen at a
depth of 28 meters in seawater?
A. 1.37 ata
B. 1.01 ata
C. 1.44 ata
D. 0.98 ata
Answer: A
Conceptual Explanation: Depth of 28m equals 3.8 ata (2.8 + 1). PO2 = 3.8 * 0.36 = 1.368,
rounded to 1.37 ata.
2. An object weighing 450 kg displaces 300 liters of seawater. How much additional seawater
must it displace to achieve neutral buoyancy?
A. 142 liters
B. 150 liters
C. 137 liters
D. 124 liters
,Answer: C
Conceptual Explanation: The object weighs 450 kg. To be neutrally buoyant in seawater
(1.03 kg/l), it must displace .03 = 436.9 liters. It currently displaces 300, so it needs
136.9 (approx 137) more.
3. Which gas law states that at a constant temperature, the volume of a gas is inversely
proportional to the pressure?
A. Dalton’s Law
B. Charles’s Law
C. Henry’s Law
D. Boyle’s Law
Answer: D
Conceptual Explanation: Boyle’s Law describes the relationship between pressure and
volume (P1V1=P2V2).
4. If a diver consumes 20 bar of air in 10 minutes at a depth of 10 meters, how much air will
they consume in 10 minutes at 30 meters, assuming the same rate of exertion?
A. 30 bar
B. 60 bar
C. 50 bar
D. 40 bar
, Answer: D
Conceptual Explanation: At 10m (2 ata), consumption is 20 bar/10 min (10 bar/ata). At
30m (4 ata), consumption is 10 bar * 4 ata = 40 bar/10 min.
5. How much faster does sound travel in water compared to air?
A. 2 times faster
B. 4 times faster
C. 10 times faster
D. Sound travels slower in water
Answer: B
Conceptual Explanation: Sound travels approximately 4 times faster in water than in air
because water is denser and less compressible.
6. Which color of the spectrum is absorbed first as a diver descends?
A. Blue
B. Red
C. Yellow
D. Green
Answer: B
