Space Heater ≠ Winterized

The saddest thing I have ever seen...

The fire in this video caused 23 MILLION DOLLARS in damage to the boats and the marina, and resulted in an environmental disaster due to all of the fuel tanks that leaked diesel and gasoline into the water.

This week's entry brings you winterizing tips. As in "how NOT to winterize your boat." While I wish I could sail away to the Caribbean (like Mike and Rebecca), I am still stuck in the land of the J.O.B. for now, so I need to store my boat every winter for the time being.

The other night, there was a boat fire in Baltimore in which two boats burned. One caught fire, burned through its dock lines, drifted across the harbor, and caught another vessel on fire, where they both burned and sank. The cause of the fire is currently under investigation.

Photo credit: United States Coast Guard

Since the cause of the fire is still under investigation, one can only speculate on how it started. But the news of the fire got me thinking about cold weather, boats, and heaters. That particular night was one of the first nights in Baltimore this year where the temperatures were forecast to get down near freezing. Some boat owners think that they can avoid or delay winterizing their vessel by putting an electric space heater on board to keep the cabin above freezing. Some even skip the space heater and just leave a 100 watt light bulb lit near the engine all winter. They feel that this eliminates the need to properly winterize the boat: draining water tanks and putting anti-freeze solution in the water lines.

There are several problems with taking this short cut for winterizing your boat:

Fire caused by spark: Most people think that the electric "radiator" type space heaters are safe on a boat because they don't have red-hot coils exposed. The problem is that many of these devices make sparks internally when their thermostat goes on and off. If your boat runs on gasoline, all electrical devices that are installed on board must meet United States Coast Guard regulation 33 CFR 183.410 for spark resistance. Devices that meet this standard are certified not to make sparks during normal operation that could ignite any gasoline vapors that may be present. Space heaters made for home use were not designed to meet these standards. A UL listed device that is deemed safe to use in your home may not be safe in a marine environment. There aren't usually flammable vapors present in your home environment, but if your vessel has gasoline tanks, there is always a chance of gasoline vapors collecting inside, especially when your boat is sealed up for the winter without regular ventilation.

Fire caused by poorly maintained or improperly connected electrical wiring:  Many boats have limited shore power service. If there is any problem at all with your shore power receptacle or boat wiring, running a 1000 watt space heater for hours on end will certainly find it. Boats have been known to burn to the waterline just because the shore power receptacle was poorly maintained or improperly connected. Leaving a high power device running unattended in an enclosed space just doesn't seem wise to me. See the following article on why shore power receptacles burn up. Fellow blogger and marine electrician Maine Sail has written an excellent article that is a topic all in itself. If you overload a poorly connected receptacle it could overheat without tripping the breaker, resulting in a fire. Make sure you TWIST LOCK the connector or it will result in a poor connection and overheat!

Fire caused by contact with a flammable object: If you think that all this can be avoided by just leaving a 100 watt light bulb lit all winter, this one's for you. That light bulb will get very hot. If it's not properly secured, it could come into contact with something flammable, and before you know it, your baby will be a pile of melted fiberglass.

Seacock with freeze damage

Freeze damage caused by a power outage: As if all of the above fire hazards are not scary enough, what happens if there is a power outage during sub-freezing temperatures?  By the time you realize there is a problem, your engine and water lines will be frozen and split.

When I first started boating, I didn't realize the difference between power available at home and the very limited power available on a boat. On a boat with a single 30 amp shore power cord, you will not be able to use more than about 24 amps. When you think about all the things that people want to run on board these days, that starts adding up fast. At home, nobody thinks twice about plugging in another cell phone, vacuum cleaner, coffee maker, etc. But on a boat with limited power available, you can quickly overload your electrical system without even realizing it. Space heaters (or anything else that generate heat with electricity) are some of the biggest power hogs - and most likely to overload circuits.


Many marinas have strict policies when it comes to boats in winter storage and do not allow any type of unattended shore power or extension cord connections to boats that are stored in the yard.

Bottom line - taking shortcuts when it comes to your boat can cost you dearly. And as bad as you think you would feel if your boat burned, would you be able to live with yourself if your boat fire also destroyed a neighboring boat because they happened to be unlucky enough to be next to you?