The idea of saturation diving takes advantage of this by providing a means for divers to remain at depth for days. From that point onward, no increase in decompression time is necessary. However, after several hours under pressure, divers' bodies become saturated with inert gas, and no further uptake occurs. This presents a problem for operations that require divers to work for extended periods at depth. The longer divers remain at depth, the more inert gas is absorbed into their body tissues, and the time required for decompression increases rapidly.

This protocol, known as decompression, can last for many hours for dives in excess of 50 metres (160 ft) when divers spend more than a few minutes at these depths. To prevent DCS, divers have to limit their rate of ascent, and pause at regular intervals to allow the pressure of gases in their body to approach equilibrium.

Medical aspects Decompression sicknessįurther information: Decompression sicknessĭecompression sickness (DCS) is a potentially fatal condition caused by bubbles of inert gas, which can occur in divers' bodies following the pressure reduction as they ascend. In 1981, at Duke University Medical Center, Bennett conducted an experiment called Atlantis III, which involved taking divers to a depth of 2,250 feet (685.8 metres), and slowly decompressing them to the surface over a period of 31-plus days, setting an early world record for depth in the process. Bennett is credited with the invention of trimix breathing gas as a method to eliminate High Pressure Nervous Syndrome. The first commercial saturation dives were performed in 1965 by Westinghouse to replace faulty trash racks at 200 feet on the Smith Mountain Dam. This was the beginning of saturation diving and the US Navy's Man-in-the-Sea Program. Once saturation is achieved, the amount of time needed for decompression depends on the depth and gases breathed. Bond began the Genesis project at the Naval Submarine Medical Research Laboratory proving that humans could in fact withstand prolonged exposure to different breathing gases and increased environmental pressures. Behnke proposed the idea of exposing humans to increased ambient pressures long enough for the blood and tissues to become saturated with inert gases in 1942. Their decompression lasted five hours leaving Nohl with a mild case of decompression sickness that resolved with recompression. On December 22, 1938, Edgar End and Max Nohl made the first intentional saturation dive by spending 27 hours breathing air at 101 feet in the County Emergency Hospital recompression facility in Milwaukee, Wisconsin. This is usually done in a decompression chamber which is part of the saturation system, and the risk of decompression sickness is significantly reduced by limiting the number of decompressions, and by decompressing at a very conservative rate. In saturation diving, the divers live under pressure in a Saturation system or 'saturation spread', a hyperbaric environment on the surface, or an ambient pressure underwater habitat, for the duration of the project or several days to weeks, as appropriate, and are decompressed to surface pressure only once, at the end of their tour of duty. This is significant because once the tissues become saturated, the time to ascend from depth, to decompress safely, will not increase with further exposure. 'Saturation' refers to the fact that the diver's tissues have absorbed the maximum partial pressure of gas possible for that depth due to the diver being exposed to breathing gas at that pressure for prolonged periods. This is a risk on every decompression, and limiting the number of decompressions can reduce the risk. ĭecompression sickness occurs when a diver with a large amount of inert gas dissolved in the body tissues is decompressed to a pressure where the gas forms bubbles which may block blood vessels or physically damage surrounding cells. Saturation diving is a diving technique that allows divers to reduce the risk of decompression sickness ('the bends') when they work at great depth for long periods of time. Saturation diver conducts deep sea salvage operations.

Diving deeper synonym