CO dangers and boats

Carbon monoxide (CO) is odorless, colorless, and deadly. There are several sources of CO poisoning on board a boat that yacht owners need to be aware of. Basically any engine that runs on gasoline produces CO in its exhaust. While carbon monoxide is odorless, colorless and pretty much otherwise undetectable to human senses, other components of motor engine exhaust are not. So if you can smell the familiar smell of exhaust fumes, then CO is definitely present!

But, your boat’s engines are not the only source of exposure to CO. Carbon monoxide is also produced when propane, charcoal, or oil is burnt, and these are common fuels for grills and other on-board appliances, such as heaters and generators.

Because there are potentially so many sources of CO on your motor yacht, it is essential that you, and all of your passengers, understand the dangers of CO, the symptoms of CO exposure, and what to do if you suspect someone has been exposed to this deadly gas for any period of time

Why is Carbon Monoxide so Deadly?

Carbon monoxide enters the bloodstream though the lungs by breathing in this dangerous gas. Exposure in a well-ventilated environment is generally not a problem. However, even brief exposure in confined spaces can kill. Once CO enters the bloodstream it very rapidly inhibits your blood’s ability to carry oxygen to and from your lungs. Death by asphyxiation soon follows.

Larger vessels such as a luxury motor yacht, often have generators that vent toward the rear of the boat. This venting poses a danger of CO poisoning to people on the rear swim deck or water platform. On larger boats, CO builds up above the water near the water platform. CO that builds up in the air space beneath the stern deck or on and near the swim deck can kill someone in seconds.

Idling at slow speeds and improperly tuned engines can add to CO build up. Wind from the aft section of the boat can increase this buildup of CO.

Back drafting can cause CO to build up inside the cabin, cockpit, and bridge when a boat is operated at a high bow angle, is improperly or heavily loaded, or has an opening that draws in exhaust.

The most common symptoms of CO poisoning are headache, dizziness, weakness, nausea, vomiting, chest pain, and confusion. Early symptoms of CO poisoning can mimic seasickness or alcohol intoxication, so it can easily be overlooked until it is too late.

The best way to escape accidental CO poisoning on a boat, is to prevent exposure to the toxic gas. Since CO cannot be seen or smelled, the best way to avoid exposure is by installing a CO detector listed by Underwriters’ Laboratories (UL) as appropriate for marine use inside the boat.

symptoms of CO poisoning

Carbon Monoxide Safety Tips and Takeaways

The best way to deal with CO is to understand the dangers, and minimize the risks and sources of exposure.

  • The most common source of CO is a running engine
  • Install and maintain a marine grade CO detector
  • CO can make you sick in seconds and high concentrations of CO can kill
  • CO symptoms are similar to and often confused with seasickness or alcohol intoxication
  • Avoid closed-off, poorly ventilated areas of a boat when its engine is running
  • Never ride or hang on a swim platform where gases accumulate when the engine is running
  • If CO is suspected, open all windows, hatches, and ports to ventilate
  • Move a person to fresh air if CO poisoning is suspected and seek medical attention
A Combination Marine Gas Detector

A Combination Marine Toxic Gas Detector

On Demand Yachting Provides Peace of Mind

Our On Demand yachting solution includes providing for all of your yacht’s safety and maintenance needs. When it comes to making sure you and all of your guests are as safe as possible, having the right crew is only part of the equation. You must make sure you have all of the right safety gear on board, and that it is all where it should be and functioning properly. That means, in the unlikely event that they are ever needed, all PFDs, fire extinguishers, smoke and CO detectors, etc., are all maintained and recharged as necessary.

Also, since increased CO output can be caused by improperly functioning engines, fuel issues, or other mechanical failure, On Demand ensures that your yacht is maintained properly.

Maintaining your yacht’s safety gear at operational readiness is just one of the services you can count on from our On Demand Yachting Solution.



Operating a motor yacht can be costly. You can reduce your expenses, and avoid costly repairs by keeping her well maintained. On Demand yachting from FYM can help. If you would like to learn more, or if you have any questions or comments about this blog post, do not hesitate to contact our Yacht Management specialists, or call us at (954) 900-9968.