1. What does scuba stand for?Scuba stands for self-contained underwater breathing apparatus.2. At what depth will you reach 1 ATM of pressure?The ambient pressure is the pressure of a surrounding atmosphere (gas or liquid) that comes in contact with a certain object. The ambient pressure, measured in psi or atm, increases by 1 atm for every 33 feet deep in water. Because you must also take into account the pressure caused naturally by the Earth’s atmosphere (1 atm), you will be at sea level with a pressure of 1 atm.3. At what depth will you reach 2 ATM of pressure?You will reach 2 atm of pressure at a depth of 33 feet. This is because you have to consider the 1 atm caused naturally by the Earth’s atmosphere and the 1 atm caused by diving 33 feet deep.4. What is a pressure squeeze?The pressure squeeze, also known as a mask squeeze, occurs when the scuba-diver fails to create equal pressures inside their diving mask. The pressure of the water is greater than the pressure inside the diver’s air spaces (air in the mask) and will continue to increase the deeper he dives. Pressure squeeze is painful to a diver, and can cause bruising on the face, nosebleed, and/or redness in the eyes.5. What are the bends?The bends, also known as decompression sickness (DCS), occurs when dissolved gases (mainly nitrogen) form bubbles in the joints, lung, heart, or skin from a diver ascending too quickly. The body’s tissues absorb nitrogen from the air tank in proportion to the surrounding pressure, but when a diver ascends too quickly, the pressure is also reduced too quickly, causing nitrogen bubbles in the body. These bubbles can cause numbness, paralysis, and problems in the brain and/or lungs.6. What are the 3 reasons you might need a scuba dive knife?The 3 reasons you may need a scuba dive knife are in case you get tangled in kelp or seaweed, you get caught in a fishing line or fishing net, or to tap on your tank to get a friend’s attention when underwater.7. What are the two basic parts of a regulator called?The two basic parts of a regulator are called the first and second stage. The first stage reduces pressure in the air tank to an intermediate pressure whereas the second stage takes the intermediate pressure and reduces it even more to the same pressure as the surrounding water to make breathing easier.8. What 2 metals are scuba tanks made from?Scuba tanks can be made from either aluminum or steel.9. Answer true or false: a. air is mostly oxygenFalse b. a properly fitted dive mask is tightFalse c. a properly fitted wetsuit is tightTrued. a pony tank is only for emergenciesTruee. it’s OK to harvest coral as long as it’s not aliveFalse10. What is RNT, on a dive table?RNT stands for residual nitrogen time. On a dive table, the RNT shows the left-over nitrogen in a diver’s body in minutes (how much time it takes the body to absorb “x” amount of nitrogen).11. What is nitrogen narcosis?Nitrogen narcosis is caused by breathing nitrogen at a high pressure. The deeper the diver goes, the higher the pressure is. Therefore, the deeper a diver goes, the greater the risk of narcosis is. Narcosis creates a feeling of “drunkenness,” slows the diver’s reaction time, and impairs their thoughts and reasoning.12. According to Charles’ law, what increases as the temperature of a gas increases?Charles’ Law describes how gases tend to expand when heated up. According to this law, when the temperature of a gas increases, the volume tends to increase as well as long as the pressure is held constant.13. According to Boyle’s law, what is increased as you decrease the volume of a gas?Boyle’s Law states that when the temperature is held constant, the pressure and volume of a gas have an inverse relationship.14. According to Henry’s law, what causes a solute to absorb more gases into solution?Henry’s Law states that at a constant temperature, the amount of a gas that dissolves in a given volume of liquid is directly proportional to the pressure of that gas in equilibrium with that liquid. Therefore, an increase in the pressure will allow the liquid to absorb more gases.15. What does a “thumbs up” sign mean?In scuba-diving, the “thumbs up” sign means “up” to indicate that they wish to end the dive.16. What does the “thumping on the chest” signal mean?When a diver thumps on their chest or places their fist across their chest, it means that they are low on air. If this happens, the diver should also use the “thumbs up” signal to show they need to ascend up to the surface.17. What does the “slitting throat” signal mean?When a diver does the “slitting throat” motion it means they are out of air.18. Which 3 air spaces are most affected when descending?When descending, the ears, sinuses (nostrils), and mask are affected. The pressure between these spaces and the surrounding water must be at equilibrium or else it will create a pressure squeeze, which hurts the diver and causes discomfort.19. Who invented the aqua-lung?The aqua-lung was invented by Emile Gagnan and Jacques Cousteau in France during the 1940’s. Gagnan was an engineer and Cousteau worked as a swimming instructor after serving in the Navy. Many aqua-lungs were created before them, but the devices were unsafe and caused injuries or even death to divers. Gagnan and Cousteau knew oxidation and air-pressure regulation would be a key component in creating a safe aqua-lung. They created a valve that adjusts air pressure automatically and supplies air whenever the diver needs it so that the air pressure within the diver stays constant with the pressure of the water. The aqua-lung they created together allows people to breath underwater without using a hose/snorkel and is still used today.20. In what kind of scuba diving does a scuba diver allow a current to carry her along?Drift diving is intentionally letting the current carry you along and should only be used by experienced divers. The current can be dangerous to beginners, causing them to lose their boat or become tired. But, the current can actually be an advantage to those who know how to use it. In a drift dive, the current can be used to get them from a certain start point to their exit point.21. What are the two most prominent scuba diving certification associations in the world?The two most prominent scuba diving certification associations in the world are the Scuba Schools International (SSI) and the Professional Association of Diving Instructors (PADI).22. Define and give some information about “the bends,” air embolisms, and oxygen toxicity. How do you get each of these illnesses? What are some side effects? Are they life threatening? How is each of them treated?The bends, also known as decompression sickness (DCS), occurs when dissolved gases (mainly nitrogen) form bubbles in the joints, lung, heart, or skin from a diver ascending too quickly. The body’s tissues absorb nitrogen from the air tank in proportion to the surrounding pressure, but when a diver ascends too quickly, the pressure is also reduced too quickly, causing nitrogen bubbles in the body. These bubbles can cause numbness, paralysis, skin rashes, and problems in the brain and/or lungs. There are 2 types of DCS. Type 1 is more mild and non-life threatening, with symptoms being pain in the joints, itchy rashes. Type 2 is life threatening and includes the same symptoms as type 1 but affects the lungs, ears, circulatory system (blood clots from nitrogen bubbles), and nervous system (spinal cord) as well. Recompression is the first treatment used when a diver gets the bends. Recompression treatment sends the diver back down in the water to allow the gas bubbles to resolve. If recompression does not work, physical therapy is needed.Air embolism occurs when air bubbles enter a vein or artery and blocks the blood flow. Similar to the bends, air embolism can happen when a diver ascends too quickly while holding their breath and failing to exhale. Because the gas expands as a diver ascends toward the surface, air spaces in the lungs can over expand and rupture. This rupture sends air bubbles into the veins/arteries, stopping the blood flow to important organs. Symptoms include difficulty breathing, respiratory failure, unconsciousness, and cardiac arrest. If a diver becomes unconscious during the ascent, they need to be immediately taken to the hospital or have CPR done.Oxygen toxicity is exposure to large amounts of oxygen at a high pressure. For scuba divers, oxygen toxicity happens when they dive past depth limits or dive with nitrox tanks, which hold less nitrogen and a higher concentration of oxygen. There are 2 types of oxygen toxicity: central nervous system and pulmonary oxygen toxicity. CNS oxygen toxicity is caused by dying or damaged cells in the central nervous system (mainly in the brain). Divers experience sudden, uncontrollable convulsions and unconsciousness. A diver who experiences CNS oxygen toxicity must be immediately taken to shallower waters to reduce the pressure of oxygen on their body. On the other hand, pulmonary oxygen toxicity affects the cells in the lungs. Those affected by pulmonary oxygen toxicity experience a range of symptoms, beginning with a burning sensation in the trachea and progressing to difficulty breathing, shortness of breath, and uncontrollable coughing. If these symptoms are ignored, the diver’s lungs can eventually stop working, causing the diver to die from lack of oxygen. A diver who experiences pulmonary oxygen toxicity must take breaks for air once they notice symptoms. These breaks usually occur every 20 minutes and last for 5 minutes. During this time, the diver breathes air, which allows his lunch to get rid of any accumulated oxygen particles.