Under an interagency agreement with the United States Coast Guard, the National Institute for Occupational Safety and Health (NIOSH) researchers evaluated carbon monoxide (CO) exposures on 16 recreational boats on Lake Norman, North Carolina, including ski boats, cabin cruisers, bow riders, deck boats, and personal watercraft. Most of the evaluated boats were speed boats or cabin cruisers, ranging in age from new to 13 years old. These boats were propelled by gasoline powered engines

the cabin cruisers also used gasoline-powered generators to provide electricity. This investigation followed a series of recent studies to reduce CO exposures and poisonings on houseboats. Epidemiologic investigations found that from 1990 to 2000, 111 CO poisonings occurred on Lake Powell, located in the Glen Canyon National Recreation Area in Utah and Arizona. Seventy-four of the poisonings occurred on houseboats and 37 poisonings occurred on other types of recreational boats. NIOSH researchers are aware of 106 CO poisonings associated with recreational boats (non-houseboats) nationwide. This study was performed for the U.S. Coast Guard to better understand how CO poisonings can occur on recreational boats and to identify the most hazardous conditions. Boats were evaluated while stationary and at multiple speeds. CO concentrations were measured by multiple real-time instruments, which were placed at different locations on the boats and at various distances behind the boats while moving. Study results indicated that stationary conditions were generally the most hazardous

however, many boats had elevated CO concentrations near the rear deck while moving. Most of the evaluated boats generated hazardous CO concentrations: peak CO concentrations often exceeded 1,000 parts per million (ppm), while average CO concentrations were well over 100 ppm at the stern (rear). Elimination of gasoline-powered marine engines without emissions controls could dramatically reduce the likelihood of CO poisonings related to recreational boats. Development and use of emission control technologies such as catalytic converters and emission control devices (ECDs), and greater use of cleaner-burning drive engines and generators could minimize the future number of CO poisonings in the marine environment.