Static apnea is a discipline in which a person holds their breath (apnea) underwater for as long as possible, and need not swim any distance. Static apnea is defined by the International Association for Development of Apnea (AIDA International) and is distinguished from the Guinness World Record for breath holding underwater, which allows the use of oxygen in preparation. It requires that the respiratory tract be immersed, with the body either in the water or at the surface, and may be performed in a pool or open water (sea, lake, river, etc.). Static apnea is the only AIDA International discipline measuring duration, and one of the three disciplines considered for the international competitions by team, with constant weight and dynamic with fins.
There is a variation of the static apnea discipline where its possible to pre-breathe 100% oxygen for up to 30 minutes prior to the breathhold. This is not part of formal competitions, but is occasionally used to set individual records.