NAUI Diver Master Exam (New 2024/ 2025 Update) Questions and Verified Answers, Exams of Marine Science and Biology

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NAUI Diver Master Exam (New 2024/ 2025

Update) Questions and Verified Answers|

100% Correct| A Grade

QUESTION

What is the difference in weight between three cubic feet (85 liters) of fresh water and the same volume of sea water? Answer: 4.8 pounds (2.2 kg)

QUESTION

A dive team wants to recover (lift) a 380 pound (172 kg)(dry weight) anchor from the bottom of the ocean. The anchor displaces 3 cubic feet (85 liters) of sea water. The bottom composition is flat and firm. How many lift bags, rated for 50 pounds (23 kg) of lift each, will it take to recover (lift) the anchor? Answer: 4 bags

QUESTION

The pressure exerted by any component gas in a mixture is termed the _____ of that gas. Answer: Partial pressure

QUESTION

The air (or other breathing mixture) that a diver breathes at depth is delivered to the diver by the regulator at _____. Answer:

Ambient pressure

QUESTION

Which of the following is an example of an injury explained by or attributed to Boyle's Law? Answer: Equalization of air spaces Reverse blocks Lung rupture injuries

QUESTION

One way that heat loss occurs during diving activity is through _____. Answer: Conduction

QUESTION

Henry's Law states that the amount of gas that will dissolve into a solution is _____ proportional to the partial pressure of that gas and _____ proportional to the absolute temperature. Answer: directly; inversely

QUESTION

The absolute pressure at 75 feet (23 meters) of sea water is: Answer: 3.27 ata/48.07 psia/3.3 bar

QUESTION

A sealed flexible container with 10 liters of air in it is submerged to a depth of 82 feet ( meters) in the ocean. Providing there is no temperature change in the water between the surface and at 82 feet (25 meters), what is the new volume in the container at 82 feet (25 meters)? Answer:

QUESTION

An air consumption rate of 40 psig (2.76 bar) per minute using a 3,000 psig/80 cubic foot ( bar/11 liter wet volume) cylinder is equal to? Answer: 1.07 cubic feet per minute (30 liters per minute)

QUESTION

If a diver has a Surface Air Consumption rate of 30 psig (2.07 bar) per minute with an 80 cubic foot/3000 psig (207 bar/11 liter wet volume) cylinder, the same cylinder will last approximately _____ minutes at a depth of 90 feet (27 meters) of sea water if the diver begins his/her ascent with 1000 psig (69 bar) remaining as a safety measure. Answer: 18

QUESTION

If a cylinder contains 80 cubic feet (2265 liters) of air at a pressure of 3000 psig (207 bar), approximately how many cubic feet (liters) of air remains in the cylinder at a pressure of 2200 psig (152 bar) if the cylinder temperature remains constant? Answer: 58.6 cubic feet (1659 liters)

QUESTION

The partial pressure of oxygen in air at a depth of 132 feet (40 meters) of sea water is _____. Answer: 1.05 ata/15.42 psia/1.06 bar

QUESTION

A dive team diving in a fresh water lake in the summer is at a depth of 20 feet (6 meters). The water temperature at this depth is 85 degrees Fahrenheit (29 degrees Celsius) and one diver in the team has 244 cubic inches (4 liters) of air in her buoyancy compensator (BC). As the team descends to a depth of 60 feet (18 meters), they pass through a thermocline and the water temperature is now 55 degrees Fahrenheit (12 degrees Celsius). If the diver with 244 cubic inches (4 liters) of air in her BC did not add or remove any air from the compensator, the new volume in her BC after arrival at 60 feet (18 meters) would be how many cubic inches (liters)? Answer: 132 cubic inches/2.16 liters

QUESTION

As we inhale air, it moves from the nose and the mouth to the _____ into the two _____ and finally to the microscopic _____. Answer: Trachea, bronchi, alveoli

QUESTION

The stimulus to breath results primarily from _____ in the bloodstream. Answer: Carbon dioxide

QUESTION

_____ is the biggest breath you can exhale.

Answer: Vital capacity

QUESTION

The risk of carbon dioxide buildup while scuba diving can usually be forestalled by _____. Answer: Avoiding slow or shallow breathing Maintaining a normal breathing pattern Being in shape for the exertion demanded by the dive planned

QUESTION

Excess breathing resistance can be caused by improperly tuned regulators and small bore snorkels. Answer: True

QUESTION

Loss of consciousness on ascent in shallow water while breathhold diving is known as _____. Answer: Shallow water blackout

QUESTION

Hyperventilation lowers the _____ in your body, the reverse of _____ buildup. _____ signals your body to breathe, and below a certain level of _____ you do not feel the urge to breathe. Answer: CO

QUESTION

Which symptom is reflective of oxygen toxicity? Answer: Muscular twitching

QUESTION

The best way to prevent overexertion is to _____. Answer: Exercise, Swim regularly with fins, Get in shape

QUESTION

Carbon monoxide levels in the blood are elevated by smoking cigarettes. Answer: true

QUESTION

What is the term for a clinical condition that follows suffocation by submersion in liquid after which there are at least 24 hours of survival? Answer: Near Drowning

QUESTION

The onset of nitrogen narcosis is characterized by _____.

Answer: Impairment of thought

QUESTION

If the elimination of gas is not fast enough to match a diver's ascent, the excessive supersaturation of gas in tissues may cause gas to come out of solution in the form of bubbles. This malady is called _____. Answer: Decompression sickness

QUESTION

What are the primary types of decompression sickness (DCS)? Answer: Musculoskeletal; Central Nervous System

QUESTION

To reverse a lower leg or foot cramp, _____. Answer: Stretch the muscles and tendons by pulling the tip of the fin toward the knee

QUESTION

A hood or tight seal can fool your carotid sinus baroreceptors into thinking that there is high blood pressure by pushing on them. Answer: True

QUESTION

Compressing your carotid arteries too much can make you _____. Answer: Dizzy, or even unconscious

QUESTION

Which malady is a result of pulmonary overinflation during ascent? Answer: Arterial gas embolism

QUESTION

Emergency treatment in the field for arterial gas embolism and decompression sickness includes _____. Answer: Having the victim breathe 100% oxygen, maintain basic life support, treat for shock, initiate transport to a hospital with a hyperbaric chamber

QUESTION

Physical damage to the body resulting from a direct change in pressure is called _____. Answer: Barotrauma

QUESTION

Clinical Hypothermia occurs when the core temperature of the human body falls below what temperature? Answer:

95 Fahrenheit (35 Celsius

QUESTION

A pressure buildup in the ear during ascent can produce a condition known as _____. Answer: Alternobaric vertigo

QUESTION

_____ is a loss of your sense of direction or position. Answer: Disorientation

QUESTION

Smoking cigarettes effects a diver in which of the following ways? Answer: Increases the level of carbon monoxide in the blood..

QUESTION

Good aerobic fitness increases _____. Answer: Your tolerance to cold

QUESTION

The current recommendation regarding pregnancy and diving, is for women _____.

Answer: Not to dive

QUESTION

Which diving instrument incorporates a Bourdon tube mechanism? Answer: Cylinder pressure gauges

QUESTION

Two benefits derived from using an electronic dive computer are _____. Answer: Accurate monitoring of ascent rate and, if executing a multi-level diving profile, avoidance of the maximum time/depth penalty

QUESTION

Green discoloration on the first stage of a scuba regulator indicates _____. Answer: Water has most likely entered the first stage

QUESTION

An air compressor used for filling scuba cylinders operates by the principle of _____. Answer: Boyle's Law

QUESTION

Dry suits form a waterproof barrier, but require undergarments to be effective in cold water

Answer: True

QUESTION

In order to make an informed decision on equipment purchase, you need to have a solid educational background concerning the _____ of diving equipment: Answer: Types, Method of operation, Care and maintenance

QUESTION

The distance between successive wave crests is defined as _____. Answer: Wavelength

QUESTION

The highest tides are called _____ tides, and the lowest tides are called _____ tides. Answer: spring; neap

QUESTION

Water rocking back and forth in a lake or a bay is defined as _____. Answer: Seiching

QUESTION

The effect of the moon on tidal action is about _____. Answer: Twice the effect of the sun

QUESTION

The type of breaking wave that produces the greatest force when breaking is the _____ breaker. Answer: Plunging

QUESTION

If the water conditions are reasonable to make a beach dive, all of the following procedures are suggested: Answer: Having your buoyancy compensator partially inflated for slight positive buoyancy. Being fully equipped. Getting as close to the water's edge as possible after timing the sets and lulls to match your entry with the smallest waves. Entering the water as quickly as possible immediately after a wave breaks, getting beyond the surf zone quickly, before the next wave breaks.

QUESTION

When waves break on shore and the backrush is funneled through a narrow opening, the condition is known as _____. Answer: A rip current

QUESTION

Currents in bodies of water are formed by _____. Answer: Surface winds, The rotation of the earth, The influence of the sun and moon

QUESTION

Water of equal temperature at all levels is most likely to be found in a lake during the _____. Answer: Spring

QUESTION

The horizontal boundary between waters of differing salinity is defined as a _____. Answer: Halocline

QUESTION

The four basic plant and animal life zones in the ocean are _____. Answer: Littoral, Planktonic, Nektonic, Benthic

QUESTION

A marine animal whose tissues are toxic, either in part or entirety is _____. Answer: Poisonous

QUESTION

Scyphozoans, or true jellyfish, possess stinging cells within their tentacles called _____. Answer: Nematocysts

QUESTION

Which creature poses a potential threat to divers in the freshwater environment? Answer: Alligator snapping turtle

QUESTION

Which of the following occurs when marine organisms concentrate pollutants in their tissues through uptake by filtering, feeding, or passive absorption? Answer: bioaccumulation

QUESTION

One way that divers can preserve the underwater environment is to: Answer: Practice spearfishing in areas legal to do so and obey local fishing regulations.

QUESTION

Compressed air, the gas that is primarily used by recreational divers, is composed of: Answer: 78.04% nitrogen, 20.94% oxygen, .033% carbon dioxide, and .934% inert gas

QUESTION

Density is defined as the _____ per unit _____ of a substance Answer: mass; volume

QUESTION

A(n) _____ is the smallest possible unit into which matter can be divided and still retain its unique characteristics. Answer: Atom

QUESTION

Archimedes' Principle states that: "an object partially or wholly immersed in a fluid is buoyed up by a force equal to the _____ of the _____ displaced by that object". Answer: weight; fluid

QUESTION

The term "half-time" is the length of time it takes a specific tissue to become _____% saturated with nitrogen. Answer: 50

QUESTION

The classic Haldane ratio of 2:1 pressure reduction has been shown to be too liberal and has been modified to about _____.

Answer: 1.58:

QUESTION

Haldane and his associates used _____ compartments to model the human body. Answer: 5

QUESTION

Prior to 1943, repetitive diving tables were unnecessary because air was surface supplied and workers stayed down until the job was complete. Answer: True

QUESTION

The _____ tables were validated using Doppler measurements of "silent bubbles," and should provide the best margin of safety based on human experiment. Answer: DCIEM

QUESTION

The recommended maximum rate of ascent for recreational scuba diving is ____ per minute. Answer: 30 feet (9 meters)

QUESTION

Special tables and procedures are required when diving at elevations ______ above sea level. Answer: 1000 feet (300 meters)

QUESTION

If a dive is particularly cold and/or strenuous, the dive team should use _____. Answer: The next greater actual dive time to determine your repetitive group letter

QUESTION

The procedure that NAUI advocates for dealing with missing required decompression stops (omitted decompression) is for divers to: Answer: Remain out of the water, rest, breathe 100% oxygen, drink fluids, be monitored for signs of decompression illness, transported to a hyperbaric facility if symptoms arise.

QUESTION

A dive team executes a dive to 110 feet (33 meters) of sea water for an actual dive time of 15 minutes. The team has a surface interval of 1 hour and 30 minutes. What is the adjusted maximum dive time available to the team on a repetitive dive to a depth of 65 feet (20 meters) of sea water? Answer: 25 minutes

QUESTION

A dive team conducts a dive to 80 feet (24 meters) of sea water for an actual dive time of 32 minutes. What is the minimum time that the same team can stay out during a surface interval and make a repetitive dive to 69 feet (21 meters) of sea water for an actual dive time of 30 minutes without required decompression? Answer: 3 hours and 21 minutes

QUESTION

A dive team spends their first 10 minutes of actual dive time during a dive at 70 feet (21 meters) of sea water. The next 20 minutes are spent at a depth of 40 feet (12 meters). What is the dive team's letter group after surfacing? Answer: F

QUESTION

A dive team conducts a dive to 95 feet (29 meters) of sea water for an actual dive time of 20 minutes. The team then has a surface interval of 2 hours. The second dive is conducted to a depth of 60 feet (18 meters) for an actual dive time of 30 minutes. The team then has a surface interval of 1 hour and 45 minutes. The team plans to make a third dive to a depth of 40 feet (12 meters). What is the team's adjusted maximum dive time for the third dive? Answer: 69 minutes

QUESTION

A dive team executes a dive and accidentally exceeds their planned actual dive time by 5 minutes. Their actual dive profile was 110 feet (34 meters) for 20 minutes. What required decompression schedule should the team follow during their ascent? Answer: A 5 minute stop at 15 feet (5 meters)

QUESTION

If the time between dives is less than 10 minutes, the surface interval is _____. Answer: Ignored

QUESTION

The type of hyperbaric chamber preferred for the treatment of diving injuries is a _____. Answer: Multiplace double-lock chamber rated for service to six atmospheres

QUESTION

Which of the following dependent emergency ascent methods is the preferred one to use? Answer: Some method of alternate air source ascent

QUESTION

Which type of ascent should be used only if a diver believes that he or she is incapable of swimming to the surface? Answer: Emergency Buoyant Ascent

QUESTION

Problems such as a loss of a mask or fin require an emergency ascent. Answer:

False

QUESTION

The safer way to deal with an out-of-air emergency may be _____. Answer: A redundant system ascent

QUESTION

An extra second stage should be mounted in the center of the chest for easy accessibility by _____. Answer: Both the donor and recipient

QUESTION

Three signs that a diver is probably on the verge of a panic reaction are _____. Answer: Low, rapid breathing, choking, and a rapid ascent for the surface

QUESTION

One of the six steps recommended by NAUI in the preparation for a rescue is _____. Answer: Completion of NAUI Scuba Rescue Diver course

QUESTION

Which technique is effective for controlling the ascent of an unconscious diver?

Answer: Do-si-do technique

QUESTION

Diving compasses need to be equipped with a(n) _____ that is aligned with the user to obtain and follow a course or bearing. Answer: Lubber line

QUESTION

Which of the following is a method for measuring distance underwater? Answer: Kick cycles

QUESTION

For most recreational diving, the _____ can function as a navigational device. Answer: Diving compass, Watch, Depth gauge

QUESTION

Which condition occurs when the needle of a compass is attracted to nearby metal or some magnetic source, such as another compass? Answer: Deviation

QUESTION

Which navigational techniques are often used to locate a dive site? Answer: Natural and compass position-fixing navigation

QUESTION

When your location is confirmed with visual checkpoints, you are navigating with _____. Answer: Pilotage

QUESTION

Which of the following are recommended technique(s) for orienting yourself in a limited visibility environment? Answer: To dive in a known area or with a buddy that has diving experience in the area, and the use of a controlled descent/ascent line.

QUESTION

A dive team conducting a night dive should have a total of how many lights (minimum) between them? Answer: 4

QUESTION

During a night dive, the "distress" signal is expressed by the following movement pattern of a diver's light _____

Answer: Rapidly swinging your light in an overhead arc

QUESTION

Besides your basic diving gear, which of the following pieces of equipment are needed for a search and light-salvage operation? Answer: Lift bag and a separate air supply for lifting.

QUESTION

Three general steps that are involved in the search for an item underwater are: Answer: Establishing depth and time limits for the search/salvage operation, discuss and agree upon emergency procedures for accidents, and select and practice the search pattern that is most likely to be use

QUESTION

Which of the search patterns listed below requires the use of a compass? Answer: The expanding box or square

QUESTION

Safety requirements for safe and effective light-salvage operations include which of the following? Answer: Being able to estimate the correct size of the lift bag, inflate it using an alternate air source, and maintain complete control of the lift bag during ascent

QUESTION

It is the responsibility of each diver to determine individually the amount of weight that is required to neutralize positive buoyancy (if present) in the water prior to any dive. The guiding principle for this determination should be to use the _____ amount of weight that will provide _____ buoyancy at 15 feet (5 meters) of depth with an empty buoyancy compensator (BC) and a nearly empty cylinder. Answer: minimum; neutral

QUESTION

Five personal limitations that must be considered prior to executing a deep dive are: Answer: Emotional status, health/fitness, training, experience, equipment.

QUESTION

For dives in the depth range between 60 and 130 feet (18 and 40 meters), primary personal diving equipment should be upgraded to include: Answer: A primary cylinder equipped with a "Y" or "H" valve or a secondary scuba cylinder which is small (approx. 15 cubic feet/425 liters) with its own regulator.

QUESTION

Three important factors to consider in the dive planning process are _____ Answer: The intended depth and duration of the dive, direction or course during the dive, and air consumption considerations for each diver in the team

QUESTION

Which of the following emergency situations may arise from a deep dive that does not go as planned? Answer: Emergency decompression Omitted decompression Instrumentation failure

QUESTION

Increased stress during a deep dive can result in mental and perceptual narrowing. This perceptual narrowing may create "task-loading" which can involve which of the following? Answer: The effects of narcosis

QUESTION

Conditions permitting, on descent most divers pause at _____ to do a quick buddy check and verify dive equipment operation/security. Answer: 15 - 33 feet (5-10 meters)

QUESTION

Non-technical recreational divers should avoid exceeding no-decompression limits for the maximum depth of any dive. Answer: true

QUESTION