Of the 116 occupational diving fatalities reported by OSHA for 1989-1997 (13 deaths per year), 49 (five per year) occurred among an estimated 3000 full-time commercial divers (OSHA, unpublished data, 1998). The average of five deaths per year corresponds to a rate of 180 deaths per 100,000 employed divers per year, which is 40 times the national average death rate for all workers. This group, which accounts for most of the commercial dive time underwater, includes divers involved in construction, maintenance, and inspection of vessels and structures such as oil rigs, bridges, and dams. The remaining 67 deaths occurred among workers who were not full-time divers; these include seafood harvest divers, search and rescue divers, scientific divers, dive instructors, and nonmilitary federal agency divers. NIOSH's National Traumatic Occupational Fatalities database reported 56 occupational diving deaths for 1989-1994 (11 deaths per year) (CDC, unpublished data, 1998); causes of deaths listed most often for divers included drowning (73% of cases), asphyxia (14%), and embolism (7%). Other causes included trauma, hypothermia, and late medical complications, but hypothermia and air embolus may be underestimated because of difficulties in diagnosing these conditions.