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 diving can be used, usually helium, when the resultant three gas mixture is called trimix, and when the nitrogen is fully substituted by helium, heliox. For dives requiring long decompression stops, divers may carry cylinders containing different gas mixtures for the various phases of the dive, typically designated as Travel, Bottom, and Decompression gases. These different gas mixtures may be used to extend bottom time, reduce inert gas narcotic effects, and reduce decompression times. To take advantage of the freedom of movement afforded by scuba equipment, the diver needs to be mobile underwater. Personal mobility is enhanced by swimfins and optionally