Freediving

Freediving, also written free-diving or free diving and known as breath-hold diving, is a mode of underwater diving that relies on holding the breath, a state called apnea, until the diver resurfaces, rather than on breathing apparatus such as scuba gear. The term skin diving was long used interchangeably with it, but in the modern recreational context skin diving usually means shallow breath-hold diving to watch marine life, while freediving is treated as a distinct discipline aimed at maximizing time, depth or distance on a single breath. Competitive freediving has a range of apnea disciplines in which competitors try to reach great depths, times or distances. The activity serves recreational, occupational and sporting purposes, including traditional fishing, spearfishing, underwater photography, synchronised swimming, underwater football, underwater rugby, underwater hockey, underwater target shooting and mermaiding. Immersion and high ambient pressure also have physiological effects that restrict the depth and duration a freediver can reach.