Saturation diving

Saturation diving is a diving technique that allows divers to reduce the risk of decompression sickness ("the bends") when they work at great depths for long periods of time.

Decompression 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. This is a risk on every decompression, and limiting the number of decompressions can reduce the risk.