All you need to know about scuba diving
The world under the sea is a vast expanse of unknown and often uncharted territories. It offers the adventurous spirit wonder, awe, and even inspiration. Thanks to Jacques Cousteau, one of the ocean’s most influential explorers, the average person, from business executive to housewife, has the opportunity to dive deep into the great blue sea and witness all that it has to offer.
When taking the first tentative steps into the world of scuba diving, it can be somewhat nervous, stepping into the unknown and worrying about the things that could go wrong. Just about the only thing people see or hear in the news about scuba diving is when something goes wrong. The millions of dives every year that work out perfectly are testament enough to the fact that the sport, or recreation, has come a long way in terms of safety during the past several decades.
The earliest stages of learning to scuba dive will bring some apprehension. We, as a human species, are not intended to breathe underwater, so for some people, getting used to the apparatus and the entire concept of breathing underwater may take a bit of getting used to. A quality scuba school will take you through the steps one at a time, and will allow you to test your mettle in a pool onsite rather than the open ocean waters.
A scuba diving certification is mandatory in most regions around the world in order to rent equipment, partake in dive tours, and even to have the air in the cylinders recharged and reloaded.
Where one chooses to earn their scuba diving certification is actually quite important as not all dive shops around the world recognize specific credentials. SSI (Scuba Schools International), for example, is the one universally recognized certification that will pretty much ensure that wherever you go, you will be recognized as a properly trained scuba diver. Of course, this isn’t an endorsement of one school over another, but several divers have learned the hard way that certain dive shops and locations don’t recognize other certifications.
A dive certification is valid for the individual’s entire lifetime, meaning there is no need, once the tests are passed and the certification earned, to have to ever test again. However, scuba diving is one of those recreations that could use a little refreshment from time to time.
Once a person dives down into the wonder that awaits beneath the waves, they never want to stop.
Scuba is an acronym for ‘Self Contained Underwater Breathing Apparatus’, which was coined by its creater, Jacques Cousteau. It is a form of underwater diving where a person is able to breathe through the use of special equipment, gases, and training. Scuba diving is commonly used for recreation, but it is also used in commercial, industrial, and rescue operations as well.
The earliest forms of diving deep underwater required the use of air to be pumped down through tubes from the surface to the divers. Scuba divers carry their own supply of air, which is a combination of nitrogen and oxygen in a compressed gas form. This allows the divers to have greater flexibility and mobility to dive deeper and to move around wherever they feel is the best location. Scuba diving allows a person to submerge for far longer periods of time, and to go deeper than snorkeling or free-diving.
Most scuba divers use swim fins to propel through the water, but current technology enables them to use the assistance of propulsion devices to carry them through the water.
The first commercially successful scuba sets were the Aqualung open-circuit units developed by Emile Gagnan and Jacques-Yves Cousteau, in which compressed gas (usually air) is inhaled from a tank and then exhaled into the water, and the descendants of these systems are still the most popular units today.
The open circuit systems were developed after Cousteau had a number of incidents of oxygen toxicity using a rebreather system, in which exhaled air is reprocessed to remove carbon dioxide. Modern versions of rebreather systems (both semi-closed circuit and closed circuit) are still available today, and form the second main type of scuba unit, most commonly used for technical diving, such as deep diving.
Controlling Buoyancy Underwater
Buoyancy is what is referred to as a person’s (or object’s) ability to float in a given surface. The deeper a person dives, the heavier they appear to be. This isn’t caused by any pressure from the water pushing down, but rather the compression of the air in the lungs, and what is known as the B.C. vest (buoyancy control vest). When air is compressed, more is required to maintain a level flotation.
To dive safely, divers must control their rate of descent and ascent in the water. Ignoring other forces such as water currents and swimming, the diver`s overall buoyancy determines whether he ascends or descends. Equipment such as the diving weighting systems, diving suits (wet, dry or semi-dry suits are used depending on the water temperature) and buoyancy compensators can be used to adjust the overall buoyancy. When divers want to remain at constant depth, they try to achieve neutral buoyancy. This minimizes gas consumption caused by swimming to maintain depth.
The downward force on the diver is the weight of the diver and his equipment minus the weight of the same volume of the liquid that he is displacing; if the result is negative, that force is upwards. The buoyancy of any object immersed in water is also affected by the density of the water. The density of fresh water is about 3% less than that of ocean water. Therefore, divers who are neutrally buoyant at one dive destination (e.g. a fresh water lake) will predictably be positively or negatively buoyant at destinations with different water densities (e.g. a tropical coral reef).
Diving weighting systems can be used to reduce the diver`s weight and cause an ascent in an emergency. Diving suits, mostly being made of compressible materials, shrink as the diver descends, and expand as the diver ascends, creating buoyancy changes. Diving in different environments also necessitates adjustments in the amount of weight carried to achieve neutral buoyancy. The diver can inject air into some diving suits to counteract the compression effect and squeeze. Buoyancy compensators allow easy and fine adjustments in the diver`s overall volume and therefore buoyancy. For open circuit divers, changes in the diver`s lung volume can be used to adjust buoyancy.
Equipment Needed for Scuba Diving
Scuba diving is considered a more exclusive recreation because of the expense for the equipment as well as the maintenance. Having quality equipment is one of the most important factors when it comes to purchasing equipment. The cheaper the items, the more at risk one places himself or herself when diving, especially when diving to deeper depths.
Most dive shops around the world have rental equipment available, but a person must be able to show their scuba certification and it must be from a dive school or organization that they recognize, or they will not rent the equipment or permit the individual to attend a particular dive.
Also, depending on where a person plans to dive will determine whether they will need other peripheral equipment. The most common is a wet suit, which is used when diving into cold waters, such as the ocean waters off of the coast of California. A wet suit means that the person will be wet, but the body will warm the water against the skin, allowing the person to avoid the risks of hypothermia. Dry suits are sealed suits in which the individual will remain dry and can wear normal clothing if preferred, while diving. Dry suits are ideal when water temperatures on the surface are considered too cold for wet suits, usually below 55 degrees Fahrenheit.
The most basic equipment needed for scuba diving, which every person should have of their own, is the face mask, or dive mask. A dive mask should be fitted to the individual. Many modern dive masks can also accommodate vision maladies, such as far sightedness. When a person has their own dive mask, they are assured that it will fit snuggly, not tight, and create a perfect seal around their face. Dive masks cover the eyes and the nose.
A snorkel is the second piece of basic equipment. Snorkels are used when the diver is on the surface. To save air in the tank, a diver will revert to the snorkel.
Swim fins are ideal for propulsion through the water and there are many different kinds of swim fins, each serving a different purpose. A dive shop professional will be able to instruct on the benefits and hindrances of one swim fin over another.
Wherever a wet suit will be necessary, swim gloves, boots, and hood will also be essential. These are made of the same material as wet suits and provide the same protection against the cold.
Beyond the most basic equipment that every scuba diver should own, comes the rest of the equipment that can be rented from dive shops, but is beneficial to own for oneself. The BC (Buoyancy Control) vest is a vest that the diver wears over the shoulders, like a backpack. To this, the tank is secured, the backup regulator is attached, and the weights as well.
Regulators. There are many kinds of regulators that can be used by divers, but the most important thing to consider is safety. A quality regulator is ideal, especially when planning dives to one hundred feet or more. Having a regulator and buoyancy control vest with a backup regulator is essential, and often required by many dive shops. The reason to have a backup regulator is in case something goes wrong with the primary regulator, or a dive companion has an issue with their equipment while on a dive.
Weights are essential in order to submerge to certain depths. Having too much weight can pose buoyancy problems and could drag a diver down too fast. Having too little weight will mean that a diver may not be able to submerge at all.