is the practice of going underwater, either with breathing apparatus (scuba diving
and surface supplied diving
) or by breath-holding.
Recreational diving is a popular activity (also called sports diving or subaquatics), and includes technical diving, recreational scuba diving, freediving, snuba, snorkeling and a range of competitive sports performed underwater.
Professional diving includes diving as part of one's occupation, and takes a range of diving activities to the underwater work site. Commercial diving, military diving, public safety diving and scientific diving are aspects of professional diving.
Freediving is a form of underwater diving that does not involve the use external breathing devices, but relies on a diver's ability to hold his or her breath until resurfacing. Activities include breath-hold spear fishing, freedive photography, apnea competitions, and to some degree, snorkeling.
The scope of this portal includes the technology supporting diving activities, the physiological and medical aspects of diving, the procedures of diving, underwater activities which are to some degree dependent on diving, economical and commercial aspects of diving, biographical information on notable divers, inventors and manufacturers of diving related equipment and researchers into aspects of diving,
A decompression dive profile in yellow showing a no-stop dive profile in red
A dive profile is a description of a diver's pressure exposure. It may be as simple as just a depth and time pair, as in: "sixty for twenty," (a stay of 20 minutes at a depth of 60 feet) or as complex as a second by second graphical representation of depth and time.
It is useful as an indication of the risks of decompression sickness and oxygen toxicity and also the volume of open-circuit breathing gas needed for a planned dive as these depend in part upon the depth and duration of the dive. A dive profile diagram is often drawn with time running from left to right and depth increasing down the page.
Jacques-Yves Cousteau in 1976
Jacques-Yves Cousteau (French pronunciation: [ʒak iv kusto]; commonly known in English as Jacques Cousteau; 11 June 1910 – 25 June 1997) was a French naval officer, explorer, ecologist, filmmaker, innovator, scientist, photographer, author and researcher who studied the sea and all forms of life in water. He co-developed the Aqua-Lung, pioneered marine conservation and was a member of the Académie française. He was also known as "le Commandant Cousteau" or "Captain Cousteau".