Dive Knife In Case The Diver example essay topic

Many people think of scuba diving as just a swim in the water, but in reality it is a very exciting, dangerous, and potentially fatal sport and activity. There are many types of scuba diving, ranging from recreational to sport to career diving. Scuba Diving is just not a swim in the water, scuba requires certification, uses technical equipment, and there is a lot of risk involved with scuba diving. Scuba, which is actually an acronym for "self-contained breathing apparatus", Allows divers to dive deeper and stay submerged longer. Scuba comes a long way from other forms of diving by using an air-tank and regulator. This is what allows them to stay under longer and dive deeper.

Scuba originally began with military and commercial applications, where it is still used today. But now, by far the largest group of divers is "Recreational Divers". These dives are practiced at depths of less than 130 feet, from these depths, divers can make a straight ascent to the surface. Diving beyond this limit requires advanced training. (Lawrence, 4) Before recreational or sport divers can take a plunge into the water, they must complete a course in scuba diving and become certified.

There are many scuba diving agencies, the largest being PADI, but there are many others, including the National Association of Underwater Instructors and the National Association of Scuba Diving Schools. All agencies require that participants be proficient swimmers, in reasonably good health, and at least 12 years of age. The course usually consists of classroom work, practice in a pool or confined body of water, and dives in open water. In the course, students learn to use diving equipment, to equalize air pressure as they descend, to swim efficiently underwater, to clear the mask if water leaks in, and to ascend safely. Because divers cannot talk to each other underwater, they also learn how to communicate underwater with hand signals. Scuba diving should always be practiced with at least one other person, and partners should remain together throughout the dive.

Certification courses teach divers the rules and advantages of the buddy system. Diving partners learn to double-check each other's equipment, share a single air supply, and assist one another should a problem occur. Neutral Buoyancy is an important skill taught in certification class. Neutral Buoyancy is a state, in which the individual neither sinks nor floats. In this weightless state, a diver conserves energy and air and keeps diving equipment off the bottom where it could be damaged. To become certified, diving students must pass a written exam and a swimming proficiency test, and successfully demonstrate newly mastered skills in four open-water dives.

Proficient divers then receive a certification card that allows them to make unsupervised dives, refill air tanks, and buy diving equipment world-wide. Stores that sell diving equipment and businesses that operate diving tours require this proof of certification. During the certification course, divers will learn everything about the technical equipment and how to use it. (Lawrence, 24) Diving equipment depends on the location of the dive, but whether sport or recreational diving, divers need several basic items of equipment: a mask, a snorkel, fins, and when necessary, and exposure suit to remain warm, air-tank and regulator. The diving mask covers the nose and eyes and enables the diver to see while underwater. A snorkel is a tube that allows the diver to breathe while floating at the water's surface.

One end fits in the diver's mouth and the other end extends above the water. The fins are worn on the feet of the diver, these help the diver propel themselves through the water with a smooth, energy-efficient motion. Wet suits are worn to keep the diver warm in warm-water temperatures and dry-suits are used in cold-water temperatures. A wet suit is made of Neoprene rubber and absorbs and traps a thin layer of water, which the diver's body heat quickly heats. In temperatures below 50 degrees, divers wear a dry-suit. To breathe under-water, scuba divers wear a metal tank filled with compressed air, and a regulator that attaches to the tank.

The regulator reduces the pressure of the air to match the surrounding water pressure, so that the diver can breathe the air comfortably. The regulator also distributes the air among four hoses. One hose delivers air to a mouthpiece, through which the diver inhales and exhales. Another hose from the regulator attaches to an adjustable air bladder called a Buoyancy Compensator devise, which the diver wears as a vest. By adding air to the BCD, the diver becomes more buoyant and rises, by releasing air, the diver becomes less buoyant and sinks.

With minor adjustments of air, the diver can achieve neutral buoyancy. A third hose attaches to pressure gauges that divers use to monitor how much air remains in the tank. A fourth hose attaches to a backup breathing device called an alternate source, or octopus. Divers also wear a belt with lead weights to help them descend and stay underwater. The weights are spaced evenly around the belt for balance. Most divers carry from 5 to 20 pounds of weight, depending on their body weight, the suit they are wearing, and where they are diving.

A quick-release buckle enables the diver to shed the belt and rise to the surface in an emergency. Emergency equipment includes a dive knife, in case the diver becomes entangled in fishing line or marine plants, and whistles, lights, or signaling devices, in case the diver is lost or swept out in a current. Divers should also have a tank of oxygen on board, along with a marine radio and a first aid kit. The diver should not only have knowledge of his equipment but a scientific knowledge of his surroundings underwater. (B&B Aquatic Adventures) The key to understanding scuba diving is the concept of pressure, and how it varies with depth. Pressure is a force or weight per unit area.

All matter, including air, has weight due to earth's gravity. Accordingly, anything exposed to air is under pressure-the weight of the atmosphere above it. This weight of air, due to gravity, is known as atmospheric pressure. Gravity keeps the atmosphere wedded to the earth.

Without gravity, earth's atmosphere would float away to outer space. Since gravity diminishes with distance from the center of the earth, air weighs less at altitude than at sea level. Literally, air at altitude is "thinner" compared to at sea level, and air becomes progressively less dense with increasing altitude. The pressure under water can cause many hazards for any type of diver.

(Reseck, 68) Hazards associated with recreational diving stem chiefly from breathing air under pressure, though a few marine animals also pose hazards. Most hazards can be avoided if divers follow the safety procedures taught in certification courses and do not attempt dives beyond their ability and experience. The single largest risk scuba divers face is pressure-related injury. Decompression sickness, also called the bends, is an injury that occurs when a diver ascends too quickly, or dives too deeply for too long. Throughout a dive, the body absorbs nitrogen. This nitrogen forms tiny bubbles in the diver's tissues and bloodstream.

If a diver ascends to the surface too quickly, these bubbles remain trapped inside the body and can cause extreme pain in joints and organs. Severe cases of decompression sickness can be fatal. For this reason, all divers attempt to ascend slowly from every dive, to allow excess nitrogen to escape the body gradually. Divers who suspect they are suffering from decompression sickness should seek medical attention immediately.

Another pressure-related injury is an air embolism. It occurs when a diver ascends too rapidly and the gases in the diver's bloodstream form a large bubble. If large enough, the bubble can block the flow of blood to the brain and be fatal. To avoid these injuries, divers calculate how long it is safe to stay at certain depths and how long they should spend on the surface before diving again. Divers must also wait at least 12 hours, and sometimes 24 hours, after a dive before flying on a plane. Because air pressure changes rapidly when a plane increases its altitude, flying to soon after diving can result in decompression sickness.

Most marine animals pose no threat to divers. In fact, divers pose far more a threat to the animals. Coral, for example, can be killed by a diver's single touch. However, a few forms of marine life can injure divers. Jellyfish, fire coral, sting coral and sea urchins are the most common threats.

In rare cases, poisonous fish and sharks can also injure people. In general, animals only attack humans when they are provoked. Scuba diving should be a visual experience, and divers should avoid touching anything - plant, animal, or object. Other risks inherent in recreational diving include running out of air, breathing contaminated air, or being injured by a boat.

Certification courses not only teach divers how to avoid these problems, but also how to treat a fellow diver should an injury occur. There are many places for a diver to explore and use his skills across the world. (encarta 98). There are many areas around the world that recreational divers prefer, but in general, most divers seek locations where the water is clear, the temperatures are warm, and the marine life is plentiful. Divers often choose to visit areas with coral reefs because they are colorful and dense with life, and provide shelter for many types of fish. The Caribbean is the most popular destination in the world.

Parts of the region are designated as marine parks or sanctuaries. Because they are protected from fishing and other human activity, these locations boast abundant aquatic plant and animal life. Similar protected areas exist throughout the world, and the South Pacific, the Indian Ocean, and the Red Sea are common dive destinations. There are many other activities related to scuba diving that an experienced diver can put their skills to the test.

(Reseck, 78) As Divers become more proficient, they usually want to take up related activities. Underwater photography and vs. ideography are the most common. Spear fishing, also called underwater hunting, is popular with some people. Many people engage in wreck diving. Shipwrecks provide a so-called artificial reef where marine life prospers, and some wrecks offer a unique look at a historical event. Divers can take special wreck-diving courses to learn how to explore a shipwreck safely.

Going inside a shipwreck without proper training can be extremely dangerous, because divers can get lost and not find their way out. Cave diving offers an opportunity to explore the geological wonders of underwater caves. It is far more dangerous than diving in open water because, once inside a cave, the diver cannot return directly to the surface for air. Cave divers use multiple tanks, backup systems, and other specialized equipment to travel safely in the complete darkness of caves.

They also carry a reel of strong, lightweight line, which they attach to a solid object outside the cave. A diver who becomes lost can retrace his or path by following the line to the mouth of the cave. Scuba Diving has come a long way from the old historic ways to become a modern sport and recreational activity. Scuba diving requires technical equipment along with a knowledge of physics and science. Scuba diving isn't just a swim in the ocean, but it is a very exciting, dangerous, and potentially fatal sport and activity..