Many people think that space is our final frontier – and that is not entirely true.While it is more difficult to get to outer space, we probably know more about thevarious planets and environments in space than we do about what lies beneaththe surface of our oceans.Just as in outer space, there is a whole environment, or ecosystem, under thewaters that cover 75% of our planet, with 70% of our planet being ocean waters.Beneath those waters there really is an entirely new world -a world full of beautyand mystery that few humans have the opportunity to experience.But the lucky few who do have the opportunity to experience this vast underwater world are able to do so because they are scuba divers. Obviously, humanbeings cannot breathe underwater, so instead, they rely on a portable respiratorysystem that is self contained.You have probably seen shows that depict scuba divers. You may have seen pictures that are taken under the water of scuba divers as well. It all looks very easy and in a sense, it is. But there is a great deal that you must know before you can participate in your first dive. Do not assume that the guy at the sports store or the dive shop can tell you everything you need to know when you purchase your diving equipment. You need to take scuba diving lessons and become a certified diver. This is necessary for your own safety, as well as for the safety of those who are diving with you. A lot can go wrong on a dive.Table of ContentsPage 3…..The Ocean – Our Most Unexplored FrontierPage 4…..The History of Scuba DivingPage 6…..Diver EducationPage 8…..Different Types of DivingPage 10…..Different Scuba Diving Skill LevelsPage 12…..Are You Healthy Enough to Dive?Page 15…..Basic Diving EquipmentPage 20…..The Divers Respiratory SystemPage 22…..Finding Your Way Under WaterPage 24…..Scuba Diving Safety GuidelinesPage 26…..About Under Water Pressure and DecompressionPage 27…..Gravity UnderwaterPage 28…..Underwater DangersPage 33…..Scuba Diving Organizations and CommunitiesPage 32…..Where To DivePage 33…..Dive VacationsPage 35…..Diver’s Glossary