To prevent or minimize decompression sickness, divers must properly plan and monitor decompression. Divers follow a decompression model to safely allow the release of excess inert gases dissolved in their body tissues, which accommodated as a result of breathing at ambient pressures greater than surface atmospheric pressure. Decompression models take into account variables such as depth and time of dive, breathing gasses, altitude, and equipment to develop appropriate procedures for safe ascent.
Divers using the anchor cable as an aid to depth control during a decompression stop during ascent.
Technical diver at a decompression stop.
Divers breathing oxygen during surface decompression in the chamber after a 240 feet (73 m) dive
Part of a saturation system
Underwater diving, as a human activity, is the practice of descending below the water's surface to interact with the environment. It is also often referred to as diving, an ambiguous term with several possible meanings, depending on context.
Immersion in water and exposure to high ambient pressure have physiological effects that limit the depths and duration possible in ambient pressure diving. Humans are not physiologically and anatomically well-adapted to the environmental conditions of diving, and various equipment has been developed to extend the depth and duration of human dives, and allow different types of work to be done.
Surface-supplied divers riding a stage to the underwater workplace
Mild barotrauma to a diver caused by mask squeeze
Views through a flat mask, above and below water
Recreational breath-hold divers in basic equipment with floats and catch bags suitable for collecting lobster or shellfish