NAUI Underwater Skills & Safety Procedures Practice Questions — Questions and Answers

Question 1: When performing a controlled emergency swimming ascent (CESA), a diver should:

Ascend as fast as possible while holding breath
Ascend slowly while continuously exhaling and making an 'ahh' sound (Correct answer)
Inflate BCD fully before starting ascent
Signal buddy and wait for assistance

Correct answer: Ascend slowly while continuously exhaling and making an 'ahh' sound

During a CESA, the diver must continuously exhale to prevent lung overexpansion as air expands with decreasing pressure.

Question 2: What is the primary purpose of the 'stop, think, breathe, act' sequence when a diver encounters a problem underwater?

To conserve air supply
To prevent panic and allow rational decision-making (Correct answer)
To signal the dive buddy
To initiate an emergency ascent

Correct answer: To prevent panic and allow rational decision-making

This sequence helps prevent panic, which is a leading factor in diving fatalities, by forcing deliberate thought before action.

Question 3: A diver notices their buddy is not responding to signals and appears rigid underwater. The first action should be:

Begin immediate ascent with the buddy
Check for consciousness by tapping and observing (Correct answer)
Remove the buddy's mask
Inflate the buddy's BCD fully

Correct answer: Check for consciousness by tapping and observing

Assessing the buddy's responsiveness is the first step before initiating any rescue or ascent procedure.

Question 4: When sharing air using an alternate air source, the donor diver should:

Remain stationary while the receiver ascends alone
Stay close to the receiver and ascend together controlling rate (Correct answer)
Immediately drop weight belts and ascend
Signal the surface before sharing air

Correct answer: Stay close to the receiver and ascend together controlling rate

Both divers must ascend together at a controlled rate while staying close to maintain the air-sharing connection.

Question 5: Which condition is most likely to cause a diver to experience mask squeeze?

Ascending too quickly
Failing to exhale through the nose during descent (Correct answer)
Wearing a mask that is too large
Breathing through the nose instead of the mouth

Correct answer: Failing to exhale through the nose during descent

During descent, increased pressure creates a vacuum inside the mask unless the diver equalizes by exhaling a small amount of air through the nose.

Question 6: What does the term 'negative entry' refer to in diving?

Entering the water with a fully deflated BCD to descend quickly (Correct answer)
Entering the water with a negative attitude
Jumping feet-first without a BCD
Entering the water with excess weight

Correct answer: Entering the water with a fully deflated BCD to descend quickly

A negative entry involves entering the water with the BCD deflated to achieve rapid descent, used in conditions with strong surface currents.

Question 7: The recommended hand signal for 'I am out of air' is:

Thumb pointing up
Hand moving across the throat in a slashing motion (Correct answer)
Fist held up with thumb and pinky extended
Both hands on top of the head

Correct answer: Hand moving across the throat in a slashing motion

The throat-slash signal universally indicates an out-of-air emergency and requests an alternate air source.

Question 8: During a safety stop at 15 feet (5 meters), a diver's computer shows they have exceeded their no-decompression limit. The diver should:

Ascend immediately to the surface
Extend the safety stop until the computer clears the obligation (Correct answer)
Descend back to depth to off-gas
Signal buddy and surface together immediately

Correct answer: Extend the safety stop until the computer clears the obligation

If a diver inadvertently exceeds NDL limits, extending the safety stop allows additional nitrogen off-gassing before surfacing.

Question 9: What is the purpose of the pre-dive buddy check (often remembered as BWRAF)?

To practice underwater communication signals
To verify all equipment is functioning and both divers are prepared (Correct answer)
To establish the dive plan and depth limits
To check weather and water conditions

Correct answer: To verify all equipment is functioning and both divers are prepared

The BWRAF buddy check (BCD, Weights, Releases, Air, Final check) ensures all equipment is properly configured before entering the water.

Question 10: A diver experiencing nitrogen narcosis at depth is most likely to exhibit which behavior?

Increased awareness and hypervigilance
Impaired judgment and euphoria similar to alcohol intoxication (Correct answer)
Rapid breathing and anxiety
Muscle cramps and joint pain

Correct answer: Impaired judgment and euphoria similar to alcohol intoxication

Nitrogen narcosis impairs cognitive function and can cause euphoria, poor decision-making, and loss of coordination at depth.

Question 11: When ascending from a dive, the maximum recommended ascent rate according to most training agencies is:

100 feet (30 meters) per minute
60 feet (18 meters) per minute
30 feet (9 meters) per minute or slower (Correct answer)
10 feet (3 meters) per minute

Correct answer: 30 feet (9 meters) per minute or slower

Most agencies, including NAUI, recommend ascending no faster than 30 feet (9 meters) per minute to allow adequate nitrogen elimination.

Question 12: A diver who surfaces far from the boat in a current should:

Swim aggressively against the current to reach the boat
Inflate SMB, conserve energy, and signal for pickup (Correct answer)
Remove BCD and weight belt to swim faster
Submerge again and navigate back underwater

Correct answer: Inflate SMB, conserve energy, and signal for pickup

Inflating an SMB (surface marker buoy) makes the diver visible while conserving energy is essential in a current.

Question 13: What is the correct response if a diver's regulator free-flows while underwater?

Immediately surface as fast as possible
Turn off the tank valve
Breathe from the side of the mouthpiece and ascend in a controlled manner (Correct answer)
Switch to snorkel

Correct answer: Breathe from the side of the mouthpiece and ascend in a controlled manner

Breathing from the side of the mouthpiece controls the flow rate while the diver safely ascends to have the regulator serviced.

Question 14: Which factor primarily determines a diver's susceptibility to decompression sickness on a given dive?

Water temperature
The amount of nitrogen absorbed based on depth and time (Correct answer)
Physical fitness level
Type of wetsuit worn

Correct answer: The amount of nitrogen absorbed based on depth and time

DCS risk is driven by the amount of nitrogen absorbed, which is directly determined by dive depth and duration.

Question 15: When performing an underwater search pattern, the 'U-pattern' is most appropriate for:

Searching a small, precisely defined area
Searching a large open area with good visibility (Correct answer)
Searching along a wall or ledge
Searching in zero visibility conditions

Correct answer: Searching a large open area with good visibility

The U-pattern (or lawn-mower pattern) covers large open areas efficiently when visibility allows divers to maintain consistent swim lanes.

Question 16: A diver finds an unconscious diver underwater with the regulator out of the mouth. The rescuer should first:

Tow the victim to the surface immediately
Replace the regulator or hold the victim's mouth closed and ascend (Correct answer)
Begin underwater CPR
Inflate the victim's BCD and let them ascend alone

Correct answer: Replace the regulator or hold the victim's mouth closed and ascend

Replacing the regulator or sealing the airway prevents water ingestion during the controlled ascent to the surface.

Question 17: What does it mean when a diver gives the 'OK' signal at the surface using one hand making a circle on top of the head?

I need assistance
I am OK (Correct answer)
I have a problem
Come to me

Correct answer: I am OK

The surface OK signal — hand forming a circle on top of the head — communicates to the boat or shore that the diver is fine.

Question 18: Which gas law explains why a balloon inflated underwater will expand as it is brought to the surface?

Henry's Law
Dalton's Law
Boyle's Law (Correct answer)
Charles' Law

Correct answer: Boyle's Law

Boyle's Law states that at constant temperature, gas volume is inversely proportional to pressure — as pressure decreases on ascent, volume increases.

Question 19: A diver with a dry suit experiences a suit inflation malfunction causing uncontrolled ascent. The correct response is:

Dump air from the BCD and activate the dry suit exhaust valve (Correct answer)
Remove weight belt immediately
Roll inverted to dump air from suit feet
Signal buddy and wait for help

Correct answer: Dump air from the BCD and activate the dry suit exhaust valve

Simultaneously dumping BCD air and using the dry suit exhaust valve helps control buoyancy during a runaway ascent.

Question 20: What is the minimum recommended surface interval before flying after recreational scuba diving?

6 hours
12 hours
18 hours (Correct answer)
24 hours

Correct answer: 18 hours

NAUI and most agencies recommend waiting at least 18 hours after multiple dives before flying to allow adequate nitrogen off-gassing.

Question 21: The purpose of a diver's surface marker buoy (SMB) deployed at the end of a dive is to:

Mark the location of the anchor line
Signal the boat or shore of the diver's surfacing location (Correct answer)
Measure current speed at depth
Indicate remaining air supply

Correct answer: Signal the boat or shore of the diver's surfacing location

An SMB alerts surface support to the diver's position during ascent, improving safety in boat traffic or open water situations.

NAUI Underwater Skills & Safety Procedures Practice Questions

When performing a controlled emergency swimming ascent (CESA), a diver should:

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