3.5 Carbon monoxide

Carbon monoxide (CO) is a colorless, odorless and tasteless gas that is unlikely to be noticed until a person is affected. All fuel burning engines and appliances produce carbon monoxide as exhaust. 

Carbon monoxide hazard.

Prolonged exposure to low concentrations or short exposure to high concentrations of CO can lead to brain damage or death.

Make sure that fresh air can circulate freely throughout the boat.

If the CO alarm activates, ensure that all persons onboard exit the closed spaces.

The symptoms of CO poisoning include nausea, headache, dizziness, ringing in ears and unconsciousness. A poisoned person's skin often turns cherry red. If you suspect CO poisoning:

  • Immediately move the person to a well-ventilated area and have them breath fresh air deeply.

  • If the person stops breathing resuscitate.

  • Be aware that the person often revives, but then relapses due to an organ failure caused by the lack of oxygen. If this happens, seek immediate medical attention. 

Preventing carbon monoxide accumulation

There is always a risk of carbon monoxide accumulation when you run the engine, generator or fuel burning appliances.

Dangerous amounts of carbon monoxide can accumulate if:  

  • The engine or generator exhaust systems leak or the hull exhausts are blocked or submerged while operating at slow speed.

  • Insufficient fresh air is circulating where people are present.

  • You run the engine or generator in a confined space.

  • Wind blows exhaust fumes toward boat occupants or into the cockpit and cabin areas. 

  • You operate the boat with the bow high or use canvas curtains.

To minimize the danger of CO accumulation:

  • Open all doors, curtains, windows, and hatches to let fresh air circulate while you run the engine, generator or fuel burning devices while the boat is anchored, moored or docked.

  • Make sure you have sufficient ventilation when you use canvas or window-type side curtains.

  • If you use a convertible top, make sure you operate the boat with the forward hatch and cabin door open.

  • Do not use fuel burning appliances, such as charcoal, propane, LPG, CNG, or alcohol cookers, in areas with no noticeable fresh air circulation when anchored, moored or docked. This applies especially to the cabin area.

  • Do not idle the engine without moving the boat for more than 15 minutes at a time.

  • Inspect the exhaust system regularly for defects. See the manufacturer's manual for instructions.

Parent topic: Safety