COMPREHENSIVE PRACTICE QUESTION BANK COMPLETE
COVERAGE OF ALL EXAM TOPICS WITH VERIFIED
ANSWERS & DETAILED RATIONALES
1. The most serious lung overexpansion injury is:
A. Pneumothorax
B. Mediastinal Emphysema
C. Arterial Gas Embolism
D. Subcutaneous Emphysema
Correct Answer: C
Rationale: Arterial Gas Embolism is the most serious lung
overexpansion injury because gas bubbles enter the arterial circulation
and can block blood flow to the brain and other vital organs, potentially
causing stroke, unconsciousness, or death.
2. If a diver is injured by harmful sea life, it is usually because of:
A. The diver's aggressive behavior
B. The diver's ignorance
C. The diver's negligence
D. All answers are correct
Correct Answer: D
Rationale: Injuries from marine life typically occur due to a combination
of factors including ignorance about the creatures, negligent behavior
such as touching or provoking them, and aggressive actions that
threaten the animal, leading to defensive reactions.
,3. The absolute pressure expressed in terms of atmospheres absolute
at 33 feet in sea water is:
A. 1 ata
B. 2 ata
C. 3 ata
D. 4 ata
Correct Answer: B
Rationale: At the surface, absolute pressure is 1 ata. In saltwater,
pressure increases by 1 ata for every 33 feet of depth. At 33 feet, water
pressure adds 1 ata, making the total absolute pressure 2 ata (1 ata
surface + 1 ata water).
4. According to Boyle's Law, if a diver takes a full breath from a scuba
tank at 66 feet and ascends to the surface without exhaling, the
volume of air in their lungs would:
A. Remain the same
B. Decrease to one-third the original volume
C. Increase to three times the original volume
D. Increase to twice the original volume
Correct Answer: C
Rationale: Boyle's Law states that pressure and volume are inversely
proportional at constant temperature. At 66 feet, the absolute pressure
is 3 ata. Upon ascending to the surface (1 ata), the pressure is reduced
by a factor of three, causing the gas volume to expand to three times its
volume at depth. This expansion creates a severe risk of lung
overexpansion injury.
5. The condition in which certain colors are diminished as depth
increases is called:
A. Refraction
,B. Turbidity
C. Diffusion
D. Absorption
Correct Answer: D
Rationale: Water absorbs different wavelengths of light at different
rates. Red light is absorbed first, followed by orange, yellow, and green.
Blue light penetrates deepest. This selective absorption of colors is what
causes colors to diminish and appear different as depth increases.
6. Earplugs while diving:
A. Aid equalization of the middle ear
B. Protect against cold
C. Should never be worn while diving
D. Protect ears from squeeze
Correct Answer: C
Rationale: Earplugs should never be worn while diving because they
create an air space that cannot be equalized as pressure increases with
depth. This can cause painful squeeze injuries, barotrauma, or rupture
of the eardrum.
7. The event that led to the use of the acronym SCUBA to describe
diving was:
A. Post-WWII equipment refinements
B. The invention of the diving helmet in circa 1800
C. The development of the demand regulator in 1943
D. The development of air pumps in the 19th century
Correct Answer: C
Rationale: The acronym SCUBA (Self-Contained Underwater Breathing
Apparatus) came into use following the development of the demand
regulator in 1943 by Jacques Cousteau and Emile Gagnan. This
, invention allowed divers to breathe underwater on demand from a
compressed air tank, revolutionizing recreational diving.
8. The first symptom of a sinus squeeze is usually:
A. A dull pain deep within the head
B. A sharp pain at the base of the neck
C. A crushing pain high in the chest
D. A sharp pain above the eyes
Correct Answer: D
Rationale: Sinus squeeze typically manifests as a sharp pain above the
eyes (frontal sinuses) or below the eyes (maxillary sinuses). This occurs
when pressure in the sinuses cannot be equalized due to congestion or
blockage of the sinus passages.
9. If you experience pain in the ear during descent:
A. Stop the descent and ascend till the pain stops
B. Abort the dive immediately
C. Place a finger in the ear canal and gently massage the ear until the
pain ceases
D. Continue the descent while gently exhaling into the mask
Correct Answer: A
Rationale: If you experience ear pain during descent, you should stop
descending and ascend slightly until the pain stops. Then attempt to
equalize again before descending. Continuing the descent with pain can
cause barotrauma or rupture of the eardrum.
10. Body heat is lost in water at a rate of _____ than in air:
A. 10 to 15 times faster
B. 25 to 30 times faster
C. 50 to 60 times faster