History of decompression research and development range of commercial, military and recreational diving. The first recorded experimental work related to decompression was conducted by Robert Boyle, who subjected experimental animals to reduced ambient pressure by use of a primitive vacuum pump. In the earliest experiments the subjects died from asphyxiation, but in later experiments, signs of what was later to become known as decompression sickness were observed. Later, when technological advances allowed the use of pressurisation of mines and caissons to exclude water ingress, miners were observed to present symptoms of what would become known as caisson disease, the bends, and decompression sickness. Once it was
Scuba set carry larger sets of three or four cylinders and most rebreathers. Additional cylinders for decompression can be sling mounted at the diver's sides. It is also possible to use a plain backpack harness to support the set, either with a horse-collar buoyancy compensator, or without any buoyancy compensator. This was the standard arrangement before the introduction of the buoyancy compensator, and is still used by some recreational and professional divers when it suits the diving operation. Surface-supplied divers are generally required to carry an emergency gas supply, also known as a bailout set, which is usually back-mounted open circuit scuba