SDI Chapter One: The Underwater Enviroment Questions And Answers Graded A+

Name three How much larger and closer do objects appear underwater and why? - ️️Water is denser than air, objects underwater appear closer than they actually are (25 percent closer). Objects also appear one third larger than they actually are. different devices that modern dive computers replace. - ️️Modern dive computers replace the need for dive tables, gauges, and different alarms (audible and/or visual). What does "SCUBA" stand for in scuba diving? - ️️It stands for self-contained underwater breathing apparatus. List the three most important scuba diving changes that occurred in the 1950s. - ️️The three most important changes were dive tables, personal dive computers (PDC), and enhanced diving equipment. What sets Scuba Diving International apart from other training agencies? - ️️SDI was the first diving agency to provide entry-level instruction and incorporates the use of dive computers. How much faster does sound move through water than air and why? - ️️Sound moves four times faster in the water than it does on land because water is about 800 times denser than air. What is the first color to be absorbed underwater? - ️️Red is the first color to disappear under water. Waves are usually caused by _________? - ️️Wind True or False? Anticipate surge action to avoid contact with stationary objects. - ️️True What types of marine life cause most diving injuries? - ️️Fire coral, jellyfish, and venomous fish on the sea floor cause the most diving injuries.List three different reasons that it is advisable to check with your local dive center before conducting diving in an area you are unfamiliar with? - ️️Local regulations, current conditions, and local medical care. What should you do if you see a potentially dangerous animal underwater and it does not leave the area? - ️️Avoid interaction with the sea life and always be respectful to the environment. If you are caught in a rip current, first swim __________________________ to the current to get out of it before swimming towards shore. - ️️Parallel When diving from shore, the best time to dive is when there is the least amount of tidal current _________ tide is when the water is neither rising nor falling and there is the least amount of tidal current. - ️️Slack tide is when the water is neither rising nor falling and there is the least amount of tidal current.