Scuba Diving Equipment and Techniques, Exams of Water and Wastewater Engineering

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Dive Master NAUI exam with correct

answers

What pressure will a scuba cylinder with a rated working pressure of 3000 psig (207 bar), be exposed to during a hydrostatic test? - correct answer-5000 psig (345 bar) Which principle represents one basis for the hydrostatic testing of scuba cylinders? - correct answer- Permanent expansion If a visual cylinder inspection reveals corrosion inside a scuba cylinder, it may require cleaning by a process called: - correct answer-Tumbling Which of the following is considered proper care of a scuba cylinder? - correct answer-Preventing moisture from entering the cylinder. Two cylinder valves in common use today are: - correct answer-The K-valve and DIN valve. Which valve is an example of a special scuba valve that is required for certain types of specialty diving such as deep diving with a single cylinder? - correct answer-Y valve Which internal valve designs are available in the first stage of scuba regulators? - correct answer-Piston; Diaphragm Which valve is unaffected by cylinder air pressure with regard to the force needed to operate the valve? - correct answer-Balanced Which regulator second stage design uses air pressure rather than mechanical leverage to open the main valve? - correct answer-Pilot

In the event of a regulator first stage malfunction, which type of valve design would be likely to eliminate air flow to the diver? - correct answer-Upstream When considering a regulator for purchase or use, an important point to remember is that certain regulators may not be capable of delivering ______ flow rates at ______ cylinder pressure during an air sharing emergency. - correct answer-high; low Which diving instrument incorporates a Bourdon tube mechanism? - correct answer-Cylinder pressure gauges Two benefits derived from using an electronic dive computer are _____. - correct answer-Accurate monitoring of ascent rate and, if executing a multi-level diving profile, avoidance of the maximum time/depth penalty Green discoloration on the first stage of a scuba regulator indicates _____. - correct answer-Water has most likely entered the first stage An air compressor used for filling scuba cylinders operates by the principle of _____. - correct answer- Boyle's Law Dry suits form a waterproof barrier, but require undergarments to be effective in cold water - correct answer-True In order to make an informed decision on equipment purchase, you need to have a solid educational background concerning the _____ of diving equipment: - correct answer-Types, Method of operation, Care and maintenance The distance between successive wave crests is defined as _____. - correct answer-Wavelength The highest tides are called _____ tides, and the lowest tides are called _____ tides. - correct answer- spring; neap Water rocking back and forth in a lake or a bay is defined as _____. - correct answer-Seiching

The effect of the moon on tidal action is about _____. - correct answer-Twice the effect of the sun The type of breaking wave that produces the greatest force when breaking is the _____ breaker. - correct answer-Plunging If the water conditions are reasonable to make a beach dive, all of the following procedures are suggested: - correct 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. When waves break on shore and the backrush is funneled through a narrow opening, the condition is known as _____. - correct answer-A rip current Currents in bodies of water are formed by _____. - correct answer-Surface winds, The rotation of the earth, The influence of the sun and moon Water of equal temperature at all levels is most likely to be found in a lake during the _____. - correct answer-Spring The horizontal boundary between waters of differing salinity is defined as a _____. - correct answer- Halocline The four basic plant and animal life zones in the ocean are _____. - correct answer-Littoral, Planktonic, Nektonic, Benthic A marine animal whose tissues are toxic, either in part or entirety is _____. - correct answer-Poisonous

Scyphozoans, or true jellyfish, possess stinging cells within their tentacles called _____. - correct answer- Nematocysts Which creature poses a potential threat to divers in the freshwater environment? - correct answer- Alligator snapping turtle Which of the following occurs when marine organisms concentrate pollutants in their tissues through uptake by filtering, feeding, or passive absorption? - correct answer-bioaccumulation One way that divers can preserve the underwater environment is to: - correct answer-Practice spearfishing in areas legal to do so and obey local fishing regulations. Compressed air, the gas that is primarily used by recreational divers, is composed of: - correct answer- 78.04% nitrogen, 20.94% oxygen, .033% carbon dioxide, and .934% inert gas Density is defined as the _____ per unit _____ of a substance - correct answer-mass; volume A(n) _____ is the smallest possible unit into which matter can be divided and still retain its unique characteristics. - correct answer-Atom 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". - correct answer-weight; fluid What is the difference in weight between three cubic feet (85 liters) of fresh water and the same volume of sea water? - correct answer-4.8 pounds (2.2 kg) 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? - correct answer-4 bags The pressure exerted by any component gas in a mixture is termed the _____ of that gas. - correct answer-Partial pressure

The air (or other breathing mixture) that a diver breathes at depth is delivered to the diver by the regulator at _____. - correct answer-Ambient pressure Which of the following is an example of an injury explained by or attributed to Boyle's Law? - correct answer-Equalization of air spaces Reverse blocks Lung rupture injuries One way that heat loss occurs during diving activity is through _____. - correct answer-Conduction 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. - correct answer- directly; inversely The absolute pressure at 75 feet (23 meters) of sea water is: - correct answer-3.27 ata/48.07 psia/3.3 bar A sealed flexible container with 10 liters of air in it is submerged to a depth of 82 feet (25 meters) in the ocean. Providing there is no temperature change in the water between the surface and at 82 feet ( meters), what is the new volume in the container at 82 feet (25 meters)? - correct answer-2. An air consumption rate of 40 psig (2.76 bar) per minute using a 3,000 psig/80 cubic foot (207 bar/ liter wet volume) cylinder is equal to? - correct answer-1.07 cubic feet per minute (30 liters per minute) If a diver has a Surface Air Consumption rate of 30 psig (2.07 bar) per minute with an 80 cubic foot/ 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. - correct answer- 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? - correct answer-58.6 cubic feet (1659 liters)

The partial pressure of oxygen in air at a depth of 132 feet (40 meters) of sea water is _____. - correct answer-1.05 ata/15.42 psia/1.06 bar 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)? - correct answer-132 cubic inches/2.16 liters As we inhale air, it moves from the nose and the mouth to the _____ into the two _____ and finally to the microscopic _____. - correct answer-Trachea, bronchi, alveoli The stimulus to breath results primarily from _____ in the bloodstream. - correct answer-Carbon dioxide _____ is the biggest breath you can exhale. - correct answer-Vital capacity The risk of carbon dioxide buildup while scuba diving can usually be forestalled by _____. - correct answer-Avoiding slow or shallow breathing Maintaining a normal breathing pattern Being in shape for the exertion demanded by the dive planned Excess breathing resistance can be caused by improperly tuned regulators and small bore snorkels. - correct answer-True Loss of consciousness on ascent in shallow water while breathhold diving is known as _____. - correct answer-Shallow water blackout 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. - correct answer-CO Which symptom is reflective of oxygen toxicity? - correct answer-Muscular twitching

The best way to prevent overexertion is to _____. - correct answer-Exercise, Swim regularly with fins, Get in shape Carbon monoxide levels in the blood are elevated by smoking cigarettes. - correct answer-true 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? - correct answer-Near Drowning The onset of nitrogen narcosis is characterized by _____. - correct answer-Impairment of thought 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 _____. - correct answer-Decompression sickness What are the primary types of decompression sickness (DCS)? - correct answer-Musculoskeletal; Central Nervous System To reverse a lower leg or foot cramp, _____. - correct answer-Stretch the muscles and tendons by pulling the tip of the fin toward the knee A hood or tight seal can fool your carotid sinus baroreceptors into thinking that there is high blood pressure by pushing on them. - correct answer-True Compressing your carotid arteries too much can make you _____. - correct answer-Dizzy, or even unconscious Which malady is a result of pulmonary overinflation during ascent? - correct answer-Arterial gas embolism Emergency treatment in the field for arterial gas embolism and decompression sickness includes _____. - correct answer-Having the victim breathe 100% oxygen, maintain basic life support, treat for shock, initiate transport to a hospital with a hyperbaric chamber

Physical damage to the body resulting from a direct change in pressure is called _____. - correct answer- Barotrauma Clinical Hypothermia occurs when the core temperature of the human body falls below what temperature? - correct answer-95 Fahrenheit (35 Celsius A pressure buildup in the ear during ascent can produce a condition known as _____. - correct answer- Alternobaric vertigo _____ is a loss of your sense of direction or position. - correct answer-Disorientation Smoking cigarettes effects a diver in which of the following ways? - correct answer-Increases the level of carbon monoxide in the blood.. Good aerobic fitness increases _____. - correct answer-Your tolerance to cold The current recommendation regarding pregnancy and diving, is for women _____. - correct answer-Not to dive The term "half-time" is the length of time it takes a specific tissue to become _____% saturated with nitrogen. - correct answer- The classic Haldane ratio of 2:1 pressure reduction has been shown to be too liberal and has been modified to about _____. - correct answer-1.58: Haldane and his associates used _____ compartments to model the human body. - correct answer- Prior to 1943, repetitive diving tables were unnecessary because air was surface supplied and workers stayed down until the job was complete. - correct answer-True

The _____ tables were validated using Doppler measurements of "silent bubbles," and should provide the best margin of safety based on human experiment. - correct answer-DCIEM The recommended maximum rate of ascent for recreational scuba diving is ____ per minute. - correct answer-30 feet (9 meters) Special tables and procedures are required when diving at elevations ______ above sea level. - correct answer-1000 feet (300 meters) If a dive is particularly cold and/or strenuous, the dive team should use _____. - correct answer-The next greater actual dive time to determine your repetitive group letter The procedure that NAUI advocates for dealing with missing required decompression stops (omitted decompression) is for divers to: - correct 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. 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? - correct answer-25 minutes 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? - correct answer-3 hours and 21 minutes 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? - correct answer-F 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 ( 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? - correct answer-69 minutes 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? - correct answer-A 5 minute stop at 15 feet (5 meters) If the time between dives is less than 10 minutes, the surface interval is _____. - correct answer-Ignored The type of hyperbaric chamber preferred for the treatment of diving injuries is a _____. - correct answer-Multiplace double-lock chamber rated for service to six atmospheres Which of the following dependent emergency ascent methods is the preferred one to use? - correct answer-Some method of alternate air source ascent Which type of ascent should be used only if a diver believes that he or she is incapable of swimming to the surface? - correct answer-Emergency Buoyant Ascent Problems such as a loss of a mask or fin require an emergency ascent. - correct answer-False The safer way to deal with an out-of-air emergency may be _____. - correct answer-A redundant system ascent An extra second stage should be mounted in the center of the chest for easy accessibility by _____. - correct answer-Both the donor and recipient Three signs that a diver is probably on the verge of a panic reaction are _____. - correct answer-Low, rapid breathing, choking, and a rapid ascent for the surface One of the six steps recommended by NAUI in the preparation for a rescue is _____. - correct answer- Completion of NAUI Scuba Rescue Diver course

Which technique is effective for controlling the ascent of an unconscious diver? - correct answer-Do-si- do technique Diving compasses need to be equipped with a(n) _____ that is aligned with the user to obtain and follow a course or bearing. - correct answer-Lubber line Which of the following is a method for measuring distance underwater? - correct answer-Kick cycles For most recreational diving, the _____ can function as a navigational device. - correct answer-Diving compass, Watch, Depth gauge Which condition occurs when the needle of a compass is attracted to nearby metal or some magnetic source, such as another compass? - correct answer-Deviation Which navigational techniques are often used to locate a dive site? - correct answer-Natural and compass position-fixing navigation When your location is confirmed with visual checkpoints, you are navigating with _____. - correct answer-Pilotage Which of the following are recommended technique(s) for orienting yourself in a limited visibility environment? - correct 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. A dive team conducting a night dive should have a total of how many lights (minimum) between them? - correct answer- During a night dive, the "distress" signal is expressed by the following movement pattern of a diver's light _____ - correct answer-Rapidly swinging your light in an overhead arc Besides your basic diving gear, which of the following pieces of equipment are needed for a search and light-salvage operation? - correct answer-Lift bag and a separate air supply for lifting.

Three general steps that are involved in the search for an item underwater are: - correct 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 Which of the search patterns listed below requires the use of a compass? - correct answer-The expanding box or square Safety requirements for safe and effective light-salvage operations include which of the following? - correct 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 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. - correct answer-minimum; neutral Five personal limitations that must be considered prior to executing a deep dive are: - correct answer- Emotional status, health/fitness, training, experience, equipment. For dives in the depth range between 60 and 130 feet (18 and 40 meters), primary personal diving equipment should be upgraded to include: - correct 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. Three important factors to consider in the dive planning process are _____ - correct 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 Which of the following emergency situations may arise from a deep dive that does not go as planned? - correct answer-Emergency decompression Omitted decompression Instrumentation failure

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? - correct answer-The effects of narcosis Conditions permitting, on descent most divers pause at _____ to do a quick buddy check and verify dive equipment operation/security. - correct answer-15-33 feet (5-10 meters) Non-technical recreational divers should avoid exceeding no-decompression limits for the maximum depth of any dive. - correct answer-true During ascent from any dive in excess of 40 feet (12 meters), divers are encouraged to make a safety stop at _____ for one minute and a precautionary stop between _____ for three to five minutes. - correct answer-One half the deepest depth of the dive, 10 feet (3 meters)/20 feet (6 meters) Enriched-air Nitrox (EAN 32), also known as NOAA Nitrox I, is a gas mixture that consists of ____% oxygen and ____% nitrogen. - correct answer-32; 68 Technical divers use methods and equipment that have been borrowed from commercial and military operations. Technical diving requires more ________, _________, and _________ than does traditional sport diving. - correct answer-training, preparation, equipment The gas of choice for technical divers that venture to depths beyond 190 feet (57.9 m) is _____. - correct answer-Trimix One serious physiological risk factor that is associated with the use of Nitrox is _____. - correct answer- Central Nervous System Oxygen Toxicity The type of scuba equipment that technical divers often use is _____. - correct answer-Conventional, but modified The U.S. Coast Guard rules state that the international code "A" flag be displayed if the vessel is conducting diving activities. The color scheme of the international code "A" flag is _____. - correct answer-Blue and white

One disadvantage of _____ keels is that they allow more bounce in swells and wind chop, causing a harsher ride. - correct answer-Inflatable On a dive charter, you might expect wetsuits to be allowed in the _____, but not in the _____. - correct answer-Galley; bunkrooms As a boat owner or skipper, you have a responsibility to _____. - correct answer-People on your boat Other boats Swimmers