NAUI Underwater Skills & Safety Procedures 4 — Questions and Answers
Question 1: 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 2: 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 3: 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 4: 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 5: 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 6: 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 7: 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 4
When performing an underwater search pattern, the 'U-pattern' is most appropriate for: