U.S. Navy diving logs were examined to determine the most frequently occurring diving accidents and to identify significant underlying factors. Of the 1174 incidents reported during the course of 706,259 dives, decompression sickness and barotraumas were the most prevalent. Mishap incidence increased significantly with dive depth. Dives for selection or experimental purposes, as well as saturation diving and surface decompressions among decompression schedule types, were at an elevated risk of terminating in an accident. Older divers were disproportionately assigned to deep dives. Eighty-one percent of diving mishaps ended in complete relief for the diver while 18% terminated in substantial relief.