Scuba is breathing gear carried on the back under water. Scuba diving, a scuba tank, learn to scuba dive.
The tank holds ordinary air, not oxygen, and the invention that made it work was the demand valve, which delivers air at the pressure of the surrounding water. The first rule of the sport is never to hold your breath while ascending.
1nounscubaBreathing gear carried on the back under water.
“They went scuba diving to see the colourful fish on the coral reef.”
scuba is equipment.
An acronym of self-contained underwater breathing apparatus, coined in the 1950s and now used as an ordinary word.
From SCUBA, self-contained underwater breathing apparatus; now usually viewed as anacronymic.
Etymology from Wiktionary, CC BY-SA