Silent Death Lurks for Pleasure Boaters: Carbon Monoxide, a Silent Killer
Carbon monoxide is invisible and has no taste or smell, so it can be present without warning. It is a potentially deadly gas produced by the burning of any carbon-based fuel. Symptoms of poisoning begin with headache, dizziness or nausea and can advance to unconsciousness and collapse. However, loss of consciousness can occur immediately if exposure is high. This is especially dangerous for people in the water since they can pass out and then sink and drown.
It is possible for fumes from an engine's exhaust to accumulate under a swim platform, in the rear cockpit or open cabin. Slow speeds, idling, or running a generator can cause carbon monoxide to accumulate even in these open areas. A tailwind can increase the accumulation.
Recent deaths have occurred during teak surfing, the practice of body surfing the currents directly behind the boat, currents provided by the boat's movement through the water. Investigations have shown carbon monoxide to be the culprit.
Safety Tips: The Coast Guard advises boaters not to participate in teak surfing. Avoid the area under the swim platform or rear deck whenever the engine or generator is running. Ensure that your boat has a working carbon monoxide detector and test its operation before each outing. Read the warnings on motors and engines posted by the boat manufacturer.
Sources: California Dept. of Boating and Waterways and U.S. Coast Guard