When alcohol and water don't mix: diving under the influence

The impairing effects of alcohol on divers' abilities to perform shallow-water entry dives were investigated under controlled conditions. Each of 13 male recreational divers, 21 to 35 years old, performed three shallow-entry dives during each of seven diving sessions at various blood alcohol concentrations (BACs). The mean group BACs of Diving Sessions 1-7 were 0, 17, 40, 71, 100, 123 and 97 mg/dl, respectively. Diving performances were videotaped and rated on their relative risk of injury due to contact with the pool bottom if the depth had actually been 3.5 feet. The data indicate progressive and significant impairment of diving performance at BACs of 40 mg/dl (or 0.04 g/dl, or 0.04%) and higher. Corroborating evidence of alcohol impairment was obtained from administering Field Sobriety Tests following Sessions 1, 5, 6 and 7; almost all subjects failed the tests at the higher BAC sessions. An analysis of the self-ratings of diving performances indicated that the divers were not aware of either their degraded performance or the increased risk of injury resulting from diving after drinking.