Boating Safety: Don't Drink and Drive

A new study from the Johns Hopkins Bloomberg School of Public Health, the University of North Carolina Highway Safety Center, and the Liberty Mutual Research Center for Safety and Health finds that alcohol consumption increases the risk of death for both passengers and operators on recreational boats, regardless of whether the boat is underway or stationary. The study appears in the December 19, 2001, issue of the Journal of the American Medical Association (JAMA).

Because the risk of boating and alcohol has never really been documented, an easy  assumption is that boating fatalities involving alcohol are a result of a drunken operator crashing the boat. But the truth is that most deaths are due to drowning and the majority involve falling overboard. Death often occurs regardless of the actions of the boat operator, and only about half of the fatalities involve operator error. About half of all deaths occur when the boat is not even moving, says lead author Gordon Smith, MD, MPH, associate professor in the Center for Injury Research and Policy at the Johns Hopkins Bloomberg School of Public Health.

Drinking while on a boat increases the risk of death in multiple ways. Someone with an elevated blood alcohol concentration is more likely to fall overboard. Once in the water, the chances of drowning are higher because alcohol can reduce an individuals ability to rescue oneself and there is an increased risk of hypothermia, explains Dr. Smith.

The study included recreational boaters 18 years and older in Maryland and North Carolina, two states with a wide diversity of waterways.  Official boating deaths from 1990 to 1998 in Maryland and North Carolina were examined and compared with controls obtained from a sample of boaters in each state during 1997 to 1999.

The results showed the relative risk of death steadily increased as the blood alcohol concentration (BAC) increased. Compared to a zero BAC, even a slightly elevated level poses a significant risk. At a BAC of .05, which is still under the legal limit for driving an automobile, a boater was four times more likely to die. A boater with a BAC of .10 was ten times more likely to die; with a BAC of .25, the risk grows to more than 50. This risk was similar for passengers and operators and was the same whether the boat was moving or stationary. 

These findings suggest that relying on the safety practice of having a designated driver, which may be effective for automobiles, would still leave boaters open to dangers. Intoxicated passengers are putting themselves at risk as much as intoxicated operators.

The current laws prohibiting operating a boat while intoxicated are thus missing a large group of people at risk. "Because studies show that 30 to 40 percent of recreational boaters surveyed typically report drinking while boating, our study points to a clear need for improved preventions efforts to reduce drinking by all boat occupants," concludes Dr. Smith.

Dr. Smith cited, for example, some Canadian provinces where alcohol use is restricted on the water for both passengers and the operator, especially in small boats (e.g., those without sleeping quarters). This approach is similar to that for automobiles, where most states have open-container laws that make it illegal to drive a car with anyone drinking in the vehicle.

Gordon S. Smith, MD, MPH, Penelope M. Keyl, MSc, PhD, Jeffrey A. Hadley, PhD, Christopher L. Bartley, MA, Robert D. Foss, PhD, William G. Tolbert, MA, and James McKnight contributed to the research and writing of this article.

This study was supported by a grant from the National Institute of Alcohol Abuse and Alcoholism.