Underwater diving is the practice of going underwater. The diver may be exposed to the ambient pressure and use breathing apparatus in scuba diving and surface supplied diving or breath-hold for the duration of the dive in freediving. The saturation diving technique can be used to reduce the risk of decompression sickness after long duration deep dives. Atmospheric diving suits may be used to isolate the diver from the effects of high ambient pressure. Although not usually considered to be diving, the use of crewed submersibles can extend the range of possible diving depths, and remotely controlled and robotic diving …