Scuba Diving International (SDI) AFS 270 Practice Test

These questions are part of the practice quiz. Start practicing

• Psoriacysts toxins claim true or false?
• The single most important rule of scuba diving is:
• Which navigation methods are used underwater?
• Risk management is defined as:
• If you are unable to make a required decompression stop:
• Objects under water appear 60 percent larger than they do on land.
• The stinging cells of many aquatic animals are called:
• Surge is the back-and-forth movement of water caused by waves passing overhead.
• The most commonly used method of finding your way under water is:
• Which of the following is commonly listed as a first aid measure for suspected decompression sickness?
• During initial buoyancy practice, you should add or remove air from your BC in large bursts until you develop an intuitive feel.
• If your buddy is unable to swim on his own, you can:
• A scuba cylinder that lasts one hour at the surface will last approximately how many minutes at 20 meters?
• During the buddy ascent, what arrangement ensures you avoid kicking the other's fins while maintaining connection?
• Which of the following describes the effect of tides on a dive site?
• In the event your computer fails, and you are not carrying a back-up computer:
• Which system is primarily involved in seasickness?
• When entering the water, how should your buoyancy compensator be configured?
• Which statement about weight systems is true?
• Which of the following is the most effective means of preventing a leg cramp from returning?
• If your buoyancy is under control, how should you hover effectively?
• Divers who are or who could be ________ should not dive.
• After exhaling to clear water from your second stage, you should:
• Which condition indicates that a diver should not participate in a dive?
• During ascent, the volume of a gas in a flexible container increases as pressure decreases. Which statement describes this behavior?
• Which statements about boat entry are correct?
• _________ who are or who could be ________ should not dive.
• Some alternate air sources are combined with a _________, to reduce the number of hoses connected to the first stage regulator.
• The easiest way to remove and replace a scuba unit underwater is to:
• Basic post-dive equipment maintenance and care includes which of the following?
• When conducting a weight check, the most accurate depth is at the end of the dive at safety-stop depth. Which statement is true?
• Which organization should be contacted for diving emergencies per the material?
• Which description best explains the formation of surf?
• A repetitive dive is defined as any dive:
• Before attaching your BC to your scuba cylinder, you should:
• Slack tide is the period between high and low tides.
• Seasickness is caused by which of the following?
• To vent air from a buoyancy compensator, which condition is true?
• To minimize risk of a lung overpressure injury during independent emergency ascent, you must:
• A common safety stop depth is 3 to 6 meters for 3-5 minutes.
• The chief factor causing nitrogen narcosis is:
• After your buddy checks that your air is turned all the way on, which action is recommended?
• Before attaching your BC to the scuba cylinder, which step should you perform?
• What is the effect of using your arms to swim underwater?
• At depth of 10 m, the volume of gas in a flexible container expands to how many times its original volume when brought to the surface?
• Not allowing alternate-air-source second stages, instrument consoles and other equipment to dangle freely primarily helps prevent which of the following?
• What is the primary purpose of proper training in buddy rescue?
• Techniques commonly used to navigate under water include:
• Which method is among the most effective means of relieving a leg cramp once it has occurred?
• To clear water from a mask, which action forms a proper seal?
• If symptoms such as euphoria, anxiety or motor skill impairment make you suspect you are suffering from narcosis, the best response is to:
• In the sweep method for recovering a second stage, which action is correct?
• A dive knife or cutting tool can be used to:
• When signaling the dive for safety, which option reflects the proper abort signal?
• Which factor explains why a wave breaks when it reaches shallow water?
• The presence of thermoclines means that:
• Which combination of symptoms could be signs of decompression sickness?
• Among the things dive buddies must agree upon prior to a dive are:
• Among the most important features to look for when selecting fins are:
• What causes a breaking wave as it approaches shore?
• What is the key technique for venting a buoyancy compensator at the surface or underwater?
• Rip currents typically flow which direction relative to shore?
• During an independent emergency ascent, you should stop periodically and inhale through your regulator because:
• If you become separated from your buddy, search for no more than ________ minute(s), then surface.
• Which of the following best describes when it is acceptable to switch to your alternate air source during a search for your primary second stage?
• If you feel pain or discomfort during descent, which is the recommended action?
• Without proper training, attempting to search for a missing buddy underwater may put you at risk.
• Which limits should a diver stay within?
• Which buddy determines the dive pace?
• Which of the following is a desirable mask skirt feature to ensure a good seal?
• Which statement about seasickness is supported by the material?
• What advantage do dive computers have over dive tables that relates to no-decompression limits?
• Desirable mask features include:
• Which methods are common for clearing water from a regulator second stage?
• A pony bottle is primarily used for:
• Among the reasons divers prefer computers over dive tables:
• After exhaling to clear water from the second stage, how should you breathe?
• Scuba cylinders must be:
• What guides a safe ascent rate during a dive?
• Hoods become necessary any time water temperatures drop below:**
• Materials commonly used to make scuba cylinders include:
• The best time to dive is during slack tide.
• Which combination of symptoms can be signs of decompression sickness?
• All of the following can help prevent decompression sickness (DCS) except:
• Decompression sickness treatment may require recompression in a hyperbaric chamber.
• At the first sign of overexertion, which action is recommended?
• Waves are measured by their height and weight.
• If you suspect that you or another diver is suffering from decompression sickness.
• ____ your dive, dive your ___
• What is the best description of risk management in diving?
• What are the three As of buoyancy control?
• A repetitive dive is defined as any dive made within which time frame of a previous dive?
• Which statement is true about descent and ascent using the buoyancy compensator?
• Which of the following is among the most effective means of relieving a leg cramp once it has occurred?
• Which statement about wave behavior in shallow water is not true?
• What feature is commonly found in many dive computers that helps track a diver's logs?
• The dive flag's primary purpose is to warn boaters of divers' presence.
• Which statement about weight systems is correct?
• Which statement about equalization is not true?
• During an alternate-air-source ascent, what is the best way to ensure you can ascend safely with your buddy?
• Which of the following statements about tides and currents is true?
• The stinging cells found in some aquatic animals are called:
• Water conducts heat away from your body ____x as fast as air does.
• Which statement best describes the pre-dive ABC check acronym?
• Regarding contact lens wearers and mask clearing, the statement 'Contact lens wearers should not close their eyes when clearing a mask' is
• Most aquatic life injuries amount to which of the following?
• Most aquatic bites are caused by defensive responses and mistaken identity.
• Which pieces of equipment should never be allowed to dangle freely?
• The first stage of a scuba regulator reduces cylinder pressure to which type of pressure?
• Divers should plan to ascend as soon as the first diver reaches which condition?
• Before a dive, what do buddies typically agree upon?
• Which maintenance tasks are typically included for scuba cylinders?
• Should you accidentally exceed your dive computer's no-decompression limit?
• If you cannot reunite with a missing buddy, what is the recommended course of action?
• Is the statement 'Taking decongestants is a good way to reduce the risk of ear or sinus squeeze' true or false?
• Which statement best describes a recommended approach to maintain neutral buoyancy underwater?
• Which type of alternate air source does not necessarily require the donor to give up his primary second stage?
• During a buddy ascent, divers should offset themselves slightly to avoid kicking the other's fins during a buddy ascent. True or false?
• Blues and grays disappear quickly as you descend.
• Which of the following statements about rip currents is true?
• For full-foot fins, which statement is true about their limitations?
• As you descend, which statement about color is true?
• Should you become entangled underwater, which statement is correct?
• As waves enter shallower water, what happens to the distance between crests?
• Which statement reflects risk factors for decompression sickness during diving activities?
• Why would a diver adjust buoyancy during a dive?
• Which measure is considered the best way to prevent or reduce nitrogen narcosis?
• Which of the following statements about waves is true?
• During the sweep method, which shoulder movement is recommended?
• Which of the following is not true when clearing a mask?
• To successfully maintain neutral buoyancy underwater, which statement is correct?
• Among the easiest ways to don a heavy weight belt, at the surface or underwater, is to:
• Which of the following is a true fact about seasickness?
• Not allowing items to dangle freely includes which of the following?
• During an alternate-air-source ascent, which hand is used to grasp the BC's deflation mechanism to control ascent rate?
• What general conclusion can be drawn about searching for a missing buddy without training?
• The primary function of a dive flag is to:
• Air passages such as the windpipe that may contain air you cannot use are called:
• Which statement about clearing water from a regulator second stage is correct?
• Which type of alternate air source does not necessarily require the donor to give up his primary second stage?
• Which statement about waves breaking is true?
• Diving safety begins with which two concepts?
• In an emergency related to suspected DCS, which actions are appropriate to take?
• To successfully vent air from a BC, which condition must be met?
• Which kick is most commonly used by recreational divers?
• Common weight systems include which of the following?
• If a diver's computer fails and there is no backup, what is a reasonable course of action?
• Not allowing alternate-air-source equipment to dangle freely provides which of the following benefits?
• The types of fins commonly used by recreational scuba divers include:
• Seasickness is caused by which of the following?
• What is the primary function of a scuba mask?
• All of the following can help prevent decompression sickness (DCS) except:
• If you will be rinsing your regulator after removing it from the cylinder, which item must be firmly in place?
• What causes most aquatic animal bites?
• Which item is commonly used to carry ballast weight on a diver?
• Which technique is described as helping prevent mask squeeze during ascent?
• Any time you cannot inhale while scuba diving (such as when a regulator is out of your mouth), you must be...
• During pre-dive checks, which component relationship is explicitly addressed?
• Your body loses the greatest amount of heat through the:
• On most repetitive dives, your computer will provide _______ no-decompression limits than on single dives.
• Under repetitive dives, how do no-decompression limits compare to single dives?
• During mask clearing, which action is recommended for the final exhalation?
• How much faster is heat transfer in water than in air? By roughly what factor?
• The first rule in handling any problem situation at the surface is to:
• Hoods are typically worn when water temperature drops below which value?
• If you experience a reverse block during ascent, what is the recommended action?
• During an independent emergency ascent, you should stop periodically and attempt to inhale through your regulator because:
• Common exposure suit types include which of the following?
• Regular dental care can help prevent which type of squeeze?
• Which of the following is true? 1: Tides can make water deeper or shallower. 2: Tidal currents can be very strong. 3: Strong tidal currents can adversely affect visibility. 4: All of the above.
• When pressurizing your scuba system, which action should you perform with the SPG?
• A redundant alternate air source such as a pony bottle is used for:
• The boundary between water layers of different temperatures is called a:
• Treatment of DCS may involve:
• If you and your buddy follow the same plan for buddy separation, you will meet on which locations?
• Your dive computer indicates you need to make a mandatory decompression stop. Your buddy's dive computer does not. You should:
• In diving safety, proper training in buddy rescue is described as doing what?
• The backward roll entry is primarily used as a method for entering from what scenario?
• Not allowing alternate-air-source second stages, instrument consoles and other equipment to dangle freely helps with what?
• For recreational divers, which combination of fins is considered common?
• If you suddenly feel ill and/or develop a headache while diving, what is the recommended action?
• Which statements are true about proper buddy positioning during an alternate-air-source ascent?
• The sun warming water near the equator, coupled with the earth's rotation, is the primary cause of permanent ocean currents.
• Which action best reduces the risk of entanglement during gear setup?
• When searching for a missing buddy, which statement best reflects the risk described in the material?
• First aid for suspected decompression sickness may include all of the following except:
• All of the following are true except:
• A sign of a rip current is?
• The key steps in descending and ascending include:
• What is the effect of dive lights on apparent color?
• Which of the following may indicate that air in a scuba cylinder is contaminated and potentially toxic?
• A regulator equipped with a conventional alternate-air-source second stage:
• Treatment for decompression sickness may require recompression in a hyperbaric chamber.
• Which statement about boat-entry practices is true?
• In terms of what buoyancy compensators (BCs) can help divers do, which statement is not true?
• Which feature helps reduce the amount of air needed to clear a mask underwater?
• The ABC pre-dive check acronym refers to which elements?
• Which action is NOT a recommended step for suspected decompression sickness?
• Which symptoms may appear with decompression sickness that affects the nervous system?
• Additional features common to many dive computers include all of the following except:
• Which action is the recommended response if narcosis symptoms occur?
• Underwater objects appear closer and larger than they do on land.
• Which statement about the reciprocal marks on your compass bezel is true?
• Divers may wish to be buoyant in which circumstances?
• During an alternate-air-source ascent, which hand placement do both divers use to hold on to the other's forearm or BC shoulder strap?
• An additional type of squeeze divers may suffer is a:
• Compared with air, sound travels approximately how many times faster in seawater?
• The preferred method to remove moisture from a dust cap before returning it to place is:
• In learning buoyancy control, which option describes how to use air adjustments?
• The chief cause of nitrogen narcosis is:
• To help prevent mildew, store equipment in a sealed container before it dries. (True or false)
• Any diver can signal to ______ the dive for any ________.
• Which organization is most closely associated with diving emergency guidance in the material?
• Which of the following describes surge?
• Which of the following is a commonly cited feature when selecting fins?
• The single most important feature when purchasing a scuba regulator is:
• To stay within the safe limits for diving, you should consider which of the following?
• Which statement correctly describes the relation of diving limits to training, equipment, and experience?
• If you cannot reunite with a missing buddy:
• With a thermocline present, surface temperatures are a good indicator of depth temperatures.
• If you suspect decompression sickness, which of the following actions is NOT listed as a first-aid measure?
• The most accurate place to conduct a weight check is:
• What is the recommended action when you cannot inhale during an independent emergency ascent?
• The primary function of a scuba regulator is to:
• Scuba cylinders must periodically undergo: