Longman Dictionary of Contemporary English
Wiktionary
n. underwater swimming using scuba equipment
WordNet
n. skin diving with scuba apparatus
Wikipedia
Scuba diving is a mode of underwater diving in which a scuba 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 breathing supplied under pressure 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 expelled to the surroundings, or a closed or semi-closed circuit rebreather, 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.
Scuba diving may be done recreationally or professionally in a number of applications, including scientific, military and public safety roles, but most commercial diving uses surface supplied diving equipment when this is practicable.
A scuba diver primarily moves underwater by using fins attached to the feet, but external propulsion can be provided by a diver propulsion vehicle, or a sled pulled from the surface. Other equipment includes a dive mask to improve underwater vision, a protective diving suit, equipment to control buoyancy, and equipment related to the specific circumstances and purpose of the dive. Scuba divers are trained in the procedures and skills appropriate to their level of certification by instructors affiliated to the diver certification organisations which issue these certifications. These include standard operating procedures for using the equipment and dealing with the general hazards of the underwater environment, and emergency procedures for self-help and assistance of a similarly equipped diver experiencing problems. A minimum level of fitness and health is required by most training organisations, but a higher level of fitness may be appropriate for some applications.
Usage examples of "scuba diving".
He had been scuba diving in Morro Bay and had managed to fire his three-barbed spear into his own ankle, and the telephone had been ringing when he got home from Hoag Memorial Hospital the next day.
He did not want to advertise the fact, just yet, that he was bringing SCUBA diving gear and two transistorized transceivers on board.
I took out my scuba diving equipment, together with air-cylinders and mask, and brought them for'ard to the wheelhouse.
Bob and Pete got swiftly into their Scuba diving gear, and they all waded out into the bay.
Deep stuff, two hundred feet, two-fifty, about the limit of safe compressed-air scuba diving.
Rick recognized the statement as a paraphrase of one in a book about scuba diving.
My own view was that Scuba diving was as risky as using a boat in the wild entrance.
Mainly business, but we always manage to work in a little scuba diving and snorkeling.
He had stopped his left-hand action because I was holding the air tube out of his reach, my back arched and my head angled, but this was defensive because my right hand was immobilized and time was already running out: in scuba diving exertion of any kind is at a heavy premium and we were making demands on oxygen that weren't going to be met.
These soldiers are heavily trained in guerrilla tactics, parachuting, wilderness survival and scuba diving, with a special emphasis on storming buildings, ship and aircraft for rescue missions.