SDI Scuba Certification Exam Study Guide Questions And Answers Verified 100% Correct

SDI Scuba Certification Exam Study Guide Questions And Answers Verified 100% Correct What is a reverse block? - ANSWER -When air cannot escape freely from an air space during ascent causes pain and discomfort in the ears and sinuses What should you do if you experience a reverse block upon ascending? - ANSWER -Stop, descend a few feet until pain subsides, wait to allow air to vent, then continue with ascent What is the most important rule in scuba diving? - ANSWER -Breathe continuously and never hold your breath What is the most serious injury that a diver could suffer from if they hold their breath upon ascending? - ANSWER -Lung over-expansion Which gas component in air causes decompression sickness and narcosis? - ANSWER -Nitrogen What medical problem can occur if a diver ascends much too rapidly for nitrogen to be slowly released? - ANSWER -Decompression sickness blood flow becomes blocked by Nitrogen bubbles List five factors that can predispose a diver to decompression sickness - ANSWER -1) age 2) repetitive dives 3) illness 4) obesity 5) drug and/or alcohol use prior to dive Describe symptoms of decompression sickness (include mild and severe signs and symptoms) - ANSWER -Rash or crackling skin caused by nitrogen bubbles in skin capillaries joint pain caused by bubbles collecting in and around joints difficulty breathing loss of sensation (numbness) unconsciousness paralysis What is the depth threshold where most scuba divers generally begin to be affected by nitrogen narcosis? - ANSWER -30 meters sea water/100 feet sea water List two possible ways a diver may feel if they become "narked" at depth - ANSWER -Extreme Euphoria Anxiety What should a diver do to alleviate the symptoms of nitrogen narcosis? - ANSWER -Ascend normally until you no longer feel the affects Which gas causes extreme headache and nausea, and in high enough concentrations causes unconsciousness and the lips and fingernail beds turn bright red? - ANSWER -Carbon monoxide (CO) What may indicate that the air in a scuba cylinder is harmful to consume? - ANSWER -Air has an odor or foul taste what should you do if you suddenly feel sick and develop a headache during a scuba dive? - ANSWER -Abort dive with a controlled ascent Breathe fresh air What is the main purpose of a snorkel? - ANSWER -It's used when a long swim on the surface is required in order to conserve air in the tanks. How do you know if a mask fits properly? - ANSWER -try on without strap by placing over eyes and breathing in through nose - If tightens against face and does not fall off, it is a proper fit Name one visual and one audible rescue signaling device - ANSWER Whistle/horn Bright-colored lift bag Name 2 basic fin designs and describe main features of each - ANSWER -1) Open Heel - heel strap, necessary when diving in cold water to enable the diver to wear neoprene boots. Adjustable sizes are available. 2) Full Foot - encloses entire foot, must be appropriate fit, allows for more efficient use of leg muscles. What is the main difference between a wet suit and a dry suit? - ANSWER -A wet suit is made of neoprene and comes in different styles for different water temperatures. Necessary for colder conditions and long dives. A dry suit is water resistant and designed with integrated inflation system. It is used for dives in temperatures of 10 degrees celsius and lower. Specialized training is required. What extra attire can enhance a diver's warmth when worn with a wet or dry suit? - ANSWER -hood hooded vest boots gloves cap Name 2 functions of wet suit boots - ANSWER -1) prevent heat loss 2) foot protection from abrasions and cuts List the functions of a dive computer - ANSWER -1) No Decompression Limit 2) Current Depth