Decompression sickness practices in lobster diving among the indigenous Miskito people, who face great economic pressures. At that time it was estimated that in the country over 2000 divers had been injured and 300 others had died since the 1970s. In the United States, it is common for medical insurance not to cover treatment for the bends that is the result of recreational diving. This is because scuba diving is considered an elective and "high-risk" activity and treatment for decompression sickness is expensive. A typical stay in a recompression chamber will easily cost several thousand dollars, even before emergency transportation is included.
Scuba set or use lower proportions of oxygen than air. In these situations divers often carry additional scuba sets, called stages, with gas mixtures with higher levels of oxygen that are primarily used to reduce decompression time in staged decompression diving. These gas mixes allow longer dives, better management of the risks of decompression sickness, oxygen toxicity or lack of oxygen (hypoxia), and the severity of nitrogen narcosis. Closed circuit scuba sets (rebreathers) provide a gas mix that is controlled to optimise the mix for the actual depth at the time. Gas cylinders used for scuba diving come in various sizes and