Snorkeling

Snorkeling or snorkelling is the practice of swimming on or through a body of water while equipped with a diving mask, a shaped tube called a snorkel, and usually fins. In cooler waters, a wetsuit may also be worn. Use of this equipment allows the snorkeler to observe underwater attractions for extended periods of time with relatively little effort.

Snorkeling is a popular recreational activity, particularly at tropical resort and scuba diving locations. The primary appeal is the opportunity to observe underwater life in a natural setting without the complicated equipment and training required for scuba diving. It appeals to all ages because of how little effort there is, and without the exhaled bubbles of scuba-diving equipment.

Snorkeling is also employed by scuba divers when on the surface, and search and rescue teams may snorkel as part of a water-based search. It is also a means to an end in underwater sports such as underwater hockey, underwater rugby and spearfishing.

Origins
Archeological evidence from as early as 3000 B.C. point to some of the earliest known divers; sponge farmers in Crete used hollow reeds to allow them to breathe while submerged in water. Snorkeling is also mentioned by Aristotle in his Parts of the Animals. He refers to divers using "instruments for respiration" resembling the elephant's trunk.

Equipment

 * Mask - Snorkelers normally wear the same kind of mask as those worn by scuba divers. By creating an airspace, the mask enables the snorkeler to see clearly underwater. All scuba diving masks consist of the lenses also known as a faceplate, a comfortable skirt, which also encloses the nose, and a head strap. There are different styles and shapes. These range from oval shaped models to lower internal volume masks and may be made from different materials; common choices are silicone and rubber.


 * Snorkel - A swimmer's snorkel is a tube typically about 30 centimeters long and with an inside diameter of between 1.5 and 2.5 centimeters, usually L- or J-shaped and fitted with a mouthpiece at the lower end, and constructed of rubber or plastic. It is used for breathing air from above the water surface when the wearer's mouth and nose are submerged. The snorkel usually has a piece of rubber that attaches the snorkel to the outside of the strap of the diving mask. An older technique is pushing the snorkel between the mask-strap and the head, but this practice increases the chances the mask will leak. The optimum design length of the snorkel tube is at most 40 centimeters (about 16 inches). A longer tube would not allow breathing when snorkeling deeper, since it would place the lungs in deeper water where the surrounding water pressure is higher. The lungs would then be unable to inflate when the snorkeler inhales, because the muscles that expand the lungs are not strong enough to operate against the higher pressure


 * Fins - provide a large surface area to push against the water. This allows you to more easily swim using your powerful leg muscles but are not necessary to snorkel. This moves you more efficiently and frees your hands and allows the swimmer to cover larger areas faster.  The majority of fins for snorkel are open heel, but there are also full foot fins available.  Quick adjust buckles are a nice feature for quickly adjusting and removing the fins when getting in and out of the water.
 * Wetsuit may be needed if snorkeling in colder water and helps provide thermal insulation, abrasion resistance and buoyancy. but even Lycra or other ‘protective clothing’ can help protect against jellyfish and other minor scrapes and bruises. Wetsuits are generally made of foamed neoprene and come in many different lengths and sizes depending on the need for coverage.

Learn
Snorkeling requires no special training, only the ability to swim and to breathe through the snorkel. However, for safety reasons, instruction and orientation from a fellow "experienced" snorkeler, tour guide, dive shop, or equipment-rental shop could be helpful for the inexperienced. Instruction generally covers equipment usage, basic safety, what to look for, and what to look out for, and conservation instructions (fragile organisms such as coral are easily damaged by snorkelers).

Flooding and clearing
Learning to clear a snorkel takes some practice. The snorkeler expels water from the snorkel either with a sharp exhalation on return to the surface (blast clearing) or by tilting the head back shortly before reaching the surface and exhaling until reaching or breaking the surface (displacement method) and facing forward again before inhaling the next breath. The displacement method expels water by displacing its presence in the snorkel with air; it is technique that takes practice but clears the snorkel with less effort, but only works when surfacing. Clearing splash water while at the surface requires blast clearing.

Do/Stay safe

 * The greatest danger to snorkelers are inshore and leisure crafts such as jet skis, speed boats and the like. A snorkeler is often submerged in the water with only the tube visible above the surface. Since these crafts can ply the same areas snorkelers visit, the chance for accidental collisions exist. Sailboats and windsurfers are especially worrisome as their quiet propulsion systems indicates that a snorkeler may be unaware of their presence, unlike any motor-driven craft, as sound travels farther underwater. A snorkeler may surface underneath one and/or be struck by such vessels. Few places demarcate small craft areas from snorkelers, unlike for regular bathers who may have areas marked by buoys. Snorkelers may therefore choose to wear bright or highly reflective colors/outfits and/or to employ dive flags to utilize being spotted easily by boaters and others
 * Never swim alone.
 * Be cautious at all times, especially when swimming at unguarded beaches. If in doubt, don’t go out!
 * Whenever possible, swim at a lifeguard protected beach.
 * Obey all instructions and orders from lifeguards.
 * If caught in a rip current, remain calm to conserve energy and think clearly.
 * Don’t fight the current. Swim out of the current in a direction following the shoreline. When out of the current, swim towards shore.
 * If you are unable to swim out of the rip current, float or calmly tread water. When out of the current, swim towards shore.
 * If you are still unable to reach shore, draw attention to yourself: face the shore, wave your arms, and yell for help.
 * Be aware of jellyfish and other dangerous animals such as sharks and salt water crocodiles.
 * Be aware of sunburn and sun protection since most snorkeling is close to the surface this can lead to many hours of direct exposure to the sun.
 * Dehydration is another concern. Hydrating well before going in the water is recommended, especially if one intends to snorkel for several hours. Proper hydration also prevents cramps.
 * Snorkelers can experience hyperventilation, which can lead in turn to “shallow water blackout″; snorkeling with a buddy (and being aware of the buddy's condition at all times) can help avoid this situation.
 * When snorkeling on or near coral reefs, care must be exercised to avoid contact with the delicate (and sometimes sharp and/or stinging) coral and its poisonous inhabitants, usually via protective gloves and by being careful of one's environment. Booties and surf shoes are especially useful as they allow trekking over reefs exposed by low tide, to drop offs or deeper waters of the outer reef - this is, however, ecologically irresponsible