Swimming done underwater with a self-contained underwater-breathing apparatus (scuba), as opposed to skin diving, which requires only a snorkel, goggles, and flippers.
Scuba gear was invented by Jacques-Yves Cousteau and Émile Gagnan in 1943. Diving clubs formed quickly as the technology became widely available. Scuba diving is used in oceanography, in underwater exploration and salvage work, in the study of water pollution, and for recreation.