Key points
- Gasoline-powered engines on boats, including onboard generators, produce carbon monoxide (CO), a colorless and odorless gas that can poison or kill someone who inhales it.
- Install and maintain a working CO detector listed by Underwriters’ Laboratories (UL) as appropriate for marine use inside the boat to prevent poisoning.
Why it's important
Larger boats, such as houseboats, sometimes 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.
Traveling at slow speeds or idling in the water can cause CO to build up in a boat's cabin, cockpit, bridge, and aft deck, or in an open area. Wind from the aft section of the boat can increase this buildup of CO.
Signs and symptoms to watch for
The most common symptoms of CO poisoning are:
- Headache
- Dizziness
- Weakness
- Nausea
- Vomiting
- Chest pain
- Confusion
High levels of CO inhalation can cause death. CO poisoning can also cause you to pass out and fall into the water and drown. A person who is sleeping or intoxicated can die from CO poisoning before ever having symptoms.
When to seek emergency care
What to do
To prevent CO poisoning:
- Properly install and maintain all fuel-burning engines and appliances.
- Recognize the symptoms of CO poisoning: headache, dizziness, weakness, nausea, vomiting, chest pain, and confusion.
- Swim and play away from areas where engines vent their exhaust.
- Watch children closely when they play on rear swim decks or water platforms.
- Never block exhaust outlets. Blocking outlets can cause CO to build up in cabin and cockpit areas.
- Dock, beach, or anchor at least 20 feet away from the nearest boat that is running a generator or engine.