page_title: Decompression equipment
hierarchical_section_title: Decompression equipment
caption_attribution_description: English: Two divers ride a stage to the sea bed from MSC rescue and salvage ship USNS Grasp in St. Kitts during Global Fleet Station 2008. Photo by MCCS Andrew McKaskle.
context_page_description: There are several categories of decompression equipment used to help divers decompress, which is the process required to allow divers to return to the surface safely after spending time underwater at higher pressures.
  Decompression obligation for a given dive profile must be calculated and monitored to ensure that the risk of decompression sickness is controlled. Some equipment is specifically for these functions, both during planning before the dive and during the dive. Other equipment is used to mark the underwater position of the diver, as a position reference in low visibility or currents, or to assist the diver's ascent and control the depth.
  Decompression may be shortened by breathing an oxygen-rich "decompression gas" such as a nitrox blend or pure oxygen. The high partial pressure of oxygen in such decompression mixes produces the effect known as the oxygen window. This decompression gas is often carried by scuba divers in side-slung cylinders. Cave divers who can only return by a single route, can leave decompression gas cylinders attached to the guideline at the points where they will be used.
context_section_description: There are several categories of decompression equipment used to help divers decompress, which is the process required to allow divers to return to the surface safely after spending time underwater at higher pressures.
  Decompression obligation for a given dive profile must be calculated and monitored to ensure that the risk of decompression sickness is controlled. Some equipment is specifically for these functions, both during planning before the dive and during the dive. Other equipment is used to mark the underwater position of the diver, as a position reference in low visibility or currents, or to assist the diver's ascent and control the depth.
  Decompression may be shortened (or accelerated) by breathing an oxygen-rich "decompression gas" such as a nitrox blend or pure oxygen. The high partial pressure of oxygen in such decompression mixes produces the effect known as the oxygen window. This decompression gas is often carried by scuba divers in side-slung cylinders. Cave divers who can only return by a single route, can leave decompression gas cylinders attached to the guideline at the points where they will be used. Surface-supplied divers will have the composition of the breathing gas controlled at the gas panel.
  Divers with long decompression obligations may be decompressed inside gas filled hyperbaric chambers in the water or at the surface, and in the extreme case, saturation divers are only decompressed at the end of a tour of duty that may be several weeks long.
caption: Surface supplied diver on diving stage
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