SSI Open Water Diver Final Exam
2026 Graded A+(Actual test 100%
verified)
Course
SSI Open Water Diver
1. What does SCUBA stand for?
A. Surface Controlled Underwater Breathing Apparatus
B. Self-Contained Underwater Breathing Apparatus
C. Submerged Controlled Underwater Breathing Air
D. Self-Controlled Underwater Breathing Assembly
Answer: B. Self-Contained Underwater Breathing Apparatus
Rationale: SCUBA refers to a self-contained underwater breathing apparatus that allows a diver
to carry their breathing gas underwater.
2. What happens to water pressure as a diver descends?
A. It decreases.
B. It remains constant.
C. It increases.
D. It disappears below 10 meters.
Answer: C. It increases.
Rationale: Pressure increases with depth. Increased pressure affects air spaces in the body and
the volume of gas-filled equipment.
3. A diver begins descending and experiences discomfort in the ears. What should the diver
do?
A. Continue descending quickly.
B. Equalize pressure before continuing the descent.
C. Remove the mask.
D. Hold the breath.
Answer: B. Equalize pressure before continuing the descent.
Rationale: Ear pressure should be equalized early and frequently during descent. A diver should
not force an equalization or continue descending when experiencing pain.
4. Which body air space is most directly affected by pressure changes during descent?
, A. Middle ear
B. Liver
C. Kidney
D. Muscle tissue
Answer: A. Middle ear
Rationale: The middle ear contains an air space that must be equalized as surrounding pressure
increases during descent.
5. What happens to the volume of air in a flexible container as pressure increases?
A. It increases.
B. It decreases.
C. It remains unchanged.
D. It becomes solid.
Answer: B. It decreases.
Rationale: According to Boyle's law, pressure and volume of a gas vary inversely when
temperature remains constant.
6. A diver takes a breath from a scuba regulator at depth. Why does the regulator provide
gas at approximately the surrounding pressure?
A. To prevent all gas from entering the lungs
B. To allow the diver to breathe against the surrounding water pressure
C. To reduce oxygen concentration
D. To eliminate nitrogen absorption
Answer: B. To allow the diver to breathe against the surrounding water pressure
Rationale: A scuba regulator reduces cylinder pressure to a pressure appropriate for breathing at
the diver's current depth.
7. What is one major reason divers should never hold their breath while ascending?
A. The lungs cannot contain oxygen.
B. Expanding gas can cause serious lung injury.
C. The regulator will stop functioning.
D. The water pressure will increase.
Answer: B. Expanding gas can cause serious lung injury.
Rationale: As ambient pressure decreases during ascent, gas in the lungs expands. Holding the
breath can prevent normal release of expanding gas and may cause pulmonary barotrauma.
8. Which principle explains why gas expands during ascent?
2026 Graded A+(Actual test 100%
verified)
Course
SSI Open Water Diver
1. What does SCUBA stand for?
A. Surface Controlled Underwater Breathing Apparatus
B. Self-Contained Underwater Breathing Apparatus
C. Submerged Controlled Underwater Breathing Air
D. Self-Controlled Underwater Breathing Assembly
Answer: B. Self-Contained Underwater Breathing Apparatus
Rationale: SCUBA refers to a self-contained underwater breathing apparatus that allows a diver
to carry their breathing gas underwater.
2. What happens to water pressure as a diver descends?
A. It decreases.
B. It remains constant.
C. It increases.
D. It disappears below 10 meters.
Answer: C. It increases.
Rationale: Pressure increases with depth. Increased pressure affects air spaces in the body and
the volume of gas-filled equipment.
3. A diver begins descending and experiences discomfort in the ears. What should the diver
do?
A. Continue descending quickly.
B. Equalize pressure before continuing the descent.
C. Remove the mask.
D. Hold the breath.
Answer: B. Equalize pressure before continuing the descent.
Rationale: Ear pressure should be equalized early and frequently during descent. A diver should
not force an equalization or continue descending when experiencing pain.
4. Which body air space is most directly affected by pressure changes during descent?
, A. Middle ear
B. Liver
C. Kidney
D. Muscle tissue
Answer: A. Middle ear
Rationale: The middle ear contains an air space that must be equalized as surrounding pressure
increases during descent.
5. What happens to the volume of air in a flexible container as pressure increases?
A. It increases.
B. It decreases.
C. It remains unchanged.
D. It becomes solid.
Answer: B. It decreases.
Rationale: According to Boyle's law, pressure and volume of a gas vary inversely when
temperature remains constant.
6. A diver takes a breath from a scuba regulator at depth. Why does the regulator provide
gas at approximately the surrounding pressure?
A. To prevent all gas from entering the lungs
B. To allow the diver to breathe against the surrounding water pressure
C. To reduce oxygen concentration
D. To eliminate nitrogen absorption
Answer: B. To allow the diver to breathe against the surrounding water pressure
Rationale: A scuba regulator reduces cylinder pressure to a pressure appropriate for breathing at
the diver's current depth.
7. What is one major reason divers should never hold their breath while ascending?
A. The lungs cannot contain oxygen.
B. Expanding gas can cause serious lung injury.
C. The regulator will stop functioning.
D. The water pressure will increase.
Answer: B. Expanding gas can cause serious lung injury.
Rationale: As ambient pressure decreases during ascent, gas in the lungs expands. Holding the
breath can prevent normal release of expanding gas and may cause pulmonary barotrauma.
8. Which principle explains why gas expands during ascent?
