U.S. Navy Air Decompression Schedule Risk Analysis.

Abstract : The purpose of this report is to provide the diving community with an estimate of the risk associated with the use of the U.S. Navy's air decompression tables. A search of the diving data bank of the U.S. Navy Safety Center for the years 1971 to 1978 revealed 16,170 dives in which an air decompression schedule was used. These dives were sorted and tabulated by decompression schedule and decompression outcome. From these data, estimates of the incidence of decompression sickness associated with each schedule were derived. The overall incidence rate for the air decompression schedules was 1.25%; the incidence rate for individual schedules having more than 50 dives ranged from 0% to 4.8%. Only 43 of the 295 U.S. Navy air decompression schedules were used 100 times or more during the past 7 years. Over one-half of the available schedules were not used at all during this 7-year period. Although the Navy's experience with individual air decompression schedules is restricted, there is little evidence that the same incidence rate would not hold for all schedules in the air decompression table. (Author)