page_title: Decompression (diving)
section_title: Decompression practice
hierarchical_section_title: Decompression (diving) / Decompression practice
caption_attribution_description: English: A scuba diver preparing to deploy a delayed surface marker buoy over a mound of wreckage near the boiler of the wreck of the SS Cape Matapan in Table Bay, near Cape Town
context_page_description: The decompression of a diver is the reduction in ambient pressure experienced during ascent from depth. It is also the process of elimination of dissolved inert gases from the diver's body, which occurs during the ascent, largely during pauses in the ascent known as decompression stops, and after surfacing until the gas concentrations reach equilibrium. Divers breathing gas at ambient pressure need to ascend at a rate determined by their exposure to pressure and the breathing gas in use. A diver who only breathes gas at atmospheric pressure when free-diving or snorkelling will not usually need to decompress, Divers using an atmospheric diving suit do not need to decompress as they are never exposed to high ambient pressure.
  When a diver descends in the water the hydrostatic pressure, and therefore the ambient pressure, rises. Because breathing gas is supplied at ambient pressure, some of this gas dissolves into the diver's blood and is transferred by the blood to other tissues.
context_section_description: The practice of decompression by divers comprises the planning and monitoring of the profile indicated by the algorithms or tables of the chosen decompression model, the equipment available and appropriate to the circumstances of the dive, and the procedures authorised for the equipment and profile to be used. There is a large range of options in all of these aspects. In many cases decompression practice takes place in a framework or "decompression system" which imposes extra constraints on diver behaviour. Such constraints may include: limiting the ascent rate; making stops during the ascent additional to any decompression stops; limiting the number of dives performed in a day; limiting the number of days of diving within a week; avoiding dive profiles that have large numbers of ascents and descents; avoiding heavy work immediately after a dive; not diving prior to flying or ascending to altitude; and organisational requirements.
caption: Diver deploying a DSMB
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