SDI Exam with correct answers

Objects under water appear: Closer and larger than they do on land What happens to colors under water As you descend, colors appear to fade, not intensify. Blues and grays are the last remaining colors at depth. Because sound travels faster under water: Sound's increases speed under water makes it harder to determine the direction from which it is coming. Water conducts heat away from your body ___ times faster than air does 25 The presence of thermoclines means that divers may require more in the way of exposure protection at depth than they will at the surface. Tides can: - make water seem deeper or shallower, stronger and difficult, adverse effect on visibility Cause of permanent ocean currents The sun warming water near the equator, coupled with the earth's rotation, is the primary cause of permanent ocean currents. Wave height and length Wave height is the distance from its highest point (crest) to its lowest point (trough). Wave length is the distance from crest to crest. formation of surf A wave encountering shallow water begins to slow at its bottom, while the top of the wave continues at its previous speed. This causes the wave to break. what is surge Surge is the back-and-forth movement of water caused by waves passing over head. What causes most aquatic animal bites? An animal's defensive response to a perceived threat & mistaken identity To be injured by an animal with poisonous spines, you must: Be the aggressor and touch the animal first. The states of buoyancy include all of the following except: Passive If you feel pain or discomfort during descent: Ascend to the point where you can comfortably equalize, and only then continue your descent. Which of the following is the best way to prevent or reduce nitrogen narcosis?