SDI chapter 1 questions and answers with complete solutions

SDI chapter 1 questions and answers with complete solutions What does SCUBA stand for? self-contained underwater breathing apparatus List the three important scuba diving changes that occurred in the 1950s. dive tables, pdc (personal dive computer), and enhanced diving equipment Name three different devices that modern dive computers replace. dive tables, gauges, and j valves What sets Scuba Diving International apart from other training agencies? SDI was the first dive training agency to provide entry-level scuba instruction that incorporates the use of dive computers. How much larger and closer do objects appear underwater and why? 33% larger and 25% closer. This happens because a dive mask creates an artificial airspace. As light travels through this airspace, it bends causing a magnifying effect. How much faster does sound move through water than air and why? 4 times faster. Water is about 800 times less denser than air. What is the first color to be absorbed underwater? red When diving from shore, the best time to dive is when there is the least amount of tidal current. ------- tide is when there is no horizontal water movement. slack If you are caught in a rip current, first swim ------- to the current to get out of it before swimming towards shore. parallel Waves are usually caused by -------. Wind pushing water on the surface Anticipate surge action to avoid contact with stationary objects. true What types of marine life cause most diving injuries? jellyfish, fire corals, and fish that live in and around the ocean floor. What should you do if you see a potentially dangerous animal underwater and it does not leave the area? don't touch the animal and respect the environment List three different reasons that it is advisable to check with your local dive center before conducting a dive in an area you are unfamiliar with. Environmental conditions, understand laws, and preparing for an emergency.