Context: Alcohol is increasingly recognized as a factor in many boating fatalities, but the association between alcohol consumption and mortality among boaters has not been well quantified.
Objectives: To determine the association of alcohol use with passengers' and operators' estimated relative risk (RR) of dying while boating.
Design, setting, and participants: Case-control study of recreational boating deaths among persons aged 18 years or older from 1990-1998 in Maryland and North Carolina (n = 221), compared with control interviews obtained from a multistage probability sample of boaters in each state from 1997-1999 (n = 3943).
Main outcome measure: Estimated RR of fatality associated with different levels of blood alcohol concentration (BAC) among boaters.
Results: Compared with the referent of a BAC of 0, the estimated RR of death increased even with a BAC of 10 mg/dL (odds ratio [OR], 1.3; 95% confidence interval [CI], 1.2-1.4). The OR was 52.4 (95% CI, 25.9-106.1) at a BAC of 250 mg/dL. The estimated RR associated with alcohol use was similar for passengers and operators and did not vary by boat type or whether the boat was moving or stationary.
Conclusions: Drinking increases the RR of dying while boating, which becomes apparent at low levels of BAC and increases as BAC increases. Prevention efforts targeted only at those operating a boat are ignoring many boaters at high risk. Countermeasures that reduce drinking by all boat occupants are therefore more likely to effectively reduce boating fatalities.