Their exhaust fan released so much carbon monoxide that the boaters were impaired, according to the Coast Guard.
A Key West Fire boat crew transferred the passengers to safety on shore for further medical assistance.
The Coast Guard wants to remind people to use caution while boating in cooler water temperatures.
“January is the coldest month in Florida where temperatures can range widely from day and night. Boaters know Jacksonville can get cool but not everyone thinks Key West can as well,” said Petty Officer 1st Class Evans Ahrens.
“People should be cautious when using generators or heating elements that they may only rarely use, particularly for those that live aboard their vessel.”
The Coast Guard recommends these safety tips:
- Check the water temperature and the weather before you head out.
- Leave a float plan with a friend or family member who is back on land.
- Keep a marine radio on board. Cell phones can be unreliable on the water.
- Have an Emergency Position Indicating Radio Beacon (EPIRB) to send out a distress signal.
- Wear a life jacket.
- Never boat under the influence.