page_title: Decompression equipment
section_title: Decompression trapezes
hierarchical_section_title: Decompression equipment / Controlling depth and ascent rate / Shot lines / Decompression trapezes
caption_attribution_description: Polski: Leszek Czarnecki wyprawa na Atol Bikini 2006
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: A decompression trapeze is a device used in recreational diving and technical diving to make decompression stops more comfortable and more secure and provide the divers' surface cover with a visual reference for the divers' position.
  It consists of a horizontal bar or bars suspended at the depth of intended decompression stops by buoys. The bars are of sufficient weight and the buoys of sufficient buoyancy that the trapeze will not easily change depth in turbulent water or if the divers experience buoyancy control problems.
  Trapezes are often used with diving shots. When diving in tidal waters at the end of slack water, the trapeze may be released from the diving shot to drift in the current as the divers make their decompression stops.
caption: Scuba diver decompressing on decompression trapeze using surface supplied gas
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