The Recreation: Outdoors: (Scuba Diving Outdoors )

Scuba Diving Outdoors Recreation.

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. (wikipedia)