SDI Exam | 65 Questions and Answers(A+ Solution guide)

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