„There you are, totally weightless, quietly soaring just above the sea floor with only the smallest amount of physical exertion. Small fish come out of their holes to look at you. How about that? You are the curiosity. You are the thing that does not belong. Perhaps this is why you dive. You are taking part in exploring man’s last ecological frontier. The very thought would excite anyone whose blood still flows in his veins. The diver is tthe observer, he looks at everything he can. He totally forgets the outside world“ (Reseck 4). When I first read this piece, I got goosebumps. For years man has explored this vast universe, spending millions of dollars, and only making a tiny scratch on its surface. For me, to be able to explore a world completely different from mine sounds like an opportunity of a lifetime. When I had to choose a topic for my senior project, scuba diving was tthe most compelling of all. This paper is about the development and use, the techniques, and the physiological concerns of scuba diving. Man underwater dates all the way back to the Iliad, but sports diving for fun and for a pprofession is fairly new. If one has ever been underwater, he should know that breathing is impossible. In the early 1940’s, Jaques Yves-Cousteau, a Frenchman, developing something that is now a very important asset to scuba diving. It is known to us as a „regulator.“ The regulator conserved air by releasing only the amount of air the Korell 2 diver needed to breathe. This increased the time the diver could stay down on one tank of air to about one hour if he were in shallow depths. Cousteau’s regulator was simple and inexpensive and marked the beginning of the sport of scuba diving. The sport grew somewhat slowly through the late 40’s and early 50’s because, although the diver could nnow stay underwater for an extended period of time, in most parts of the world the water was so cold that he was forced to leave the water after a short time (Reseck 16). In the early 1950’s, rubber suits were designed. They were used to keep the diver warm. These old „dry suits“ were worn over long underwear and sweat suits or sweaters. The clothing acted as an insulator, and the rubber suit was used to simply keep the iinsulation dry. But when the easily punctured „dry suits“ were torn, the insulation became wet, thus causing the insulation to be ineffective. But a new suit, called the „wet suit“ was invented. The wet suit actually strapped a thin layer of water next to the diver’s body, which soon heated up to body temperature and acted as insulation. Nowadays, foam neoprene is used for all wet suits. When the demand for wet suits increased, manufacturers developed the standard small, medium, and large sizes. As the market continued to grow, the neoprene material was improved by making it softer and more flexible. A backing was also added on the neoprene to increase its durability and service. The market grew larger still, and ready made suits came in extra small, small, medium, medium large, large, and extra large sizes. Today, almost anyone can walk into a store and come out with a good suit that fits (Reseck 17). Korell 3 Scuba diving can be very dangerous and, if not approached safely, one must know the precautions and dangers before jumping into water to dive. There are several ways to dive underwater. One way is the Pike Surface dive. Start from a prone pposition on the surface. Sweep both arms back toward the hips at the same time and bend sharply at the hips so that the head and trunk point directly toward the bottom of the pool. With palms facing forward, bring the arms up forcibly, in line with the head, and lift both legs–straight and together–out of the water so that they, too, form a straight line with the body. Let the weight of the legs force the body to submerge. Do not kick until the feet are below the surface, then either kick for greater depth or straighten out for an underwater swim (Counsilman and Drinkwater 29). Another dive is the Feet First dive. Tread water over the spot where the dive is to be made. Raise the body out of the water with a strong kick and a downward push with the hands and arms. Then straighten legs, point toes, and raise the arms overhead. The weight of the upper body and the arms will force the entire body under the surface. When the downward motion stops, bend at the hips and, with and underwater pike, either continue the dive headfirst or level off to swim (Counsilman and Drinkwater 229). The mask, the snorkel, and the fins are three of the most important tools in diving. Occasionally, water may seep into the mask, or the mask may become dislodged and flooded while the diver is under the surface. Sometimes a diver can simply surface when the mask becomes flooded, but it may be necessary to clear the mask before surfacing in order to have visibility during the ascent. Grasp the mask Korell 4 and pull it away from the face to allow the mask to flood. Roll the head to one side so that the face plate is turned to the surface. Hold the uppermost side of the mask firmly against the face, and exhale into the mask through the nose. The air trapped in the mask will fill the space and force the water out under the bottom edge. Some divers prefer to clear the mask by holding it firmly against the forehead and tilting the head back until they are looking up at the surface before blowing into it. Common errors are failing to tilt the mask toward the surface, pressing the top edge so tightly against the face that the mask is pulled away from other
parts of the face, and allowing air to escape under the top edge of the mask by failing to hold the mask firmly in place (Counsilman and Drinkwater 31-33). The snorkel is a critical tool for breathing underwater. Most divers attach the snorkel to the mask strap so it cannot be easily lost underwater. First, slip the mouthpiece into the mouth and bite down on the rubber projections with teeth. The wide flange should fit between the teeth and lips. IIt is common for the snorkel, stand in shallow water, take a deep breath and submerge until the snorkel is completely filled. Straighten out until the back of the head is clear of the water but the face is still submerged. Next, make a quick hard blow to clear the water from the tube. Now you should have a clear snorkel (Counsilman and Drinkwater 33). The fins are what make you move through the water in a faster and less rrigorous fashion. Walking in fins on land should not be done because they are extremely awkward and could cause a fall. In shallow water, it is easier to walk backwards if you move slowly and slide the feet along the bbottom. When the diver is Korell 5 equipped with fins, the hands are rarely used and held at the sides to help keep the body straight. When the fins are used, the most common kick is the flutter kick and is used on the surface and underwater. The legs are to stay relaxed. To get the full effect of the fins and to avoid necessary fatigue, kick at a slightly slower pace than usual. The toes should stay pointed, and the fins should be completely submerged (Counsilman and Drinkwater 33-34). When diving, the „buddy system“ should always be used, and all equipment should be placed in reach from the dive site. A buddy is there to help you check your ggear and, when underwater, to help you in case of ...