Diving equipment is equipment used by underwater divers to make diving activities possible, easier, safer and/or more comfortable. This may be equipment primarily intended for this purpose, or equipment intended for other purposes which is found to be suitable for diving use.
Equipment which is used for underwater work or other activities which is not directly related to the activity of diving, or which has not been designed or modified specifically for underwater use by divers is excluded.
A submarine snorkel is a device which allows a submarine to operate submerged while still taking in air from above the surface. Navy personnel often refer to it as the snort.
Until the advent of nuclear power, submarines were designed to operate on the surface most of the time and submerge only for evasion or for daylight attacks. In 1940, at night, a U-boat was safer on the surface than submerged because ASDIC sonar could detect boats underwater but was almost useless against a surface vessel. However, with continued improvement in methods of radar detection as the war progressed, the U-boat was forced to spend more time underwater running on electric motors that gave speeds of only a few knots and with very limited endurance.
A scuba set is any breathing set that is carried entirely by an underwater diver and provides the diver with breathing gas at the ambient pressure. (Scuba is an acronym for self-contained underwater breathing apparatus). Although strictly speaking the scuba set is only the diving equipment which is required for providing breathing gas to the diver, general usage includes the harness by which it is carried, and those accessories which are integral parts of the harness and breathing apparatus assembly, such as a jacket or wing style buoyancy compensator and instruments mounted in a combined housing with the pressure gauge, and in the looser sense it is used to refer to any diving equipment used by the scuba diver, though this would more commonly be termed scuba equipment. Scuba is overwhelmingly the most common underwater breathing equipment used by recreational divers. A scuba set is also used in professional diving when it provides advantages, usually of mobility and range, over surface supplied systems.
Two basic configurations of scuba are in general use:
Scuba diving is a form of underwater diving in which a diver uses a self contained underwater breathing apparatus (scuba) to breathe underwater.
Unlike other modes of diving, which rely either on breath-hold or on air pumped from the surface, scuba divers carry their own source of breathing gas, (usually compressed air), allowing them greater freedom of movement than with an air line or diver's umbilical and longer underwater endurance than breath-hold. Scuba equipment may be open circuit, in which exhaled gas is exhausted to the surroundings, or closed or semi-closed circuit, in which the breathing gas is scrubbed to remove carbon dioxide, and the oxygen used is replenished from a supply of feed gas before being re-breathed.
Underwater diving is the practice of going underwater, either with breathing apparatus (scuba diving and surface supplied diving) or by breath-holding (freediving).
Underwater diving methods include Free-diving, Scuba diving, Surface-supplied diving, Saturation diving, and diving in Atmospheric diving suits.
Underwater sports is a group of competitive sports using one or a combination of the following underwater diving techniques - breath-hold, snorkelling or scuba including the use of equipment such as diving masks and fins. These sports are conducted in the natural environment at sites such as open water and sheltered or confined water such as lakes and in artificial aquatic environments such as swimming pools. Underwater sports include the following - aquathlon (i.e. underwater wrestling), finswimming, free-diving, spearfishing, sport diving, underwater football, underwater hockey, underwater ice hockey, underwater orienteering, underwater photography, underwater rugby, underwater target shooting and underwater video. The governance of these sports involves some controversies.
Most of these sports are fin based.]not relevant[ The inclusion of the word "underwater", in the group noun for these sports, is, perhaps, unwarranted but the phrase has become fixed.]according to whom?[ The term is almost certainly derived from the name of Confédération Mondiale des Activités Subaquatiques (CMAS), which is also known as the World Underwater Federation.]attribution needed[ Most have surface based elements.]not relevant[ There are many fin-based sports that are not included in this category of sports.]not relevant[ Freediving includes a few events that are not fin-based (static apnea, dynamic apnea without fins amongst others).