The heater that iced up

THEY SAY THAT IF you have a heater on your boat, you can extend your sailing season by six weeks or so at each end. I have never been swayed by that argument. Having spent most of my life in the sub-tropics, I have no love of sailing in the cold. Or the cold-and-rain, as happens around here. So I reckon there’s no need for a heater on a boat in this region.
There was one on a little Cape Dory 25D I once owned. We found her on an island in the San Juans, and sailed her home one bitter-cold day in February, when there was ice on deck. We had an overnight stop in a marina in Anacortes, where we ran into an old sailing friend. He offered us an electric heater because he said a cold night was forecast, but we scoffed and turned him away. “We have a nice Force 10 heater installed,” we said.
After a meal ashore, we came back to the boat and lit the heater. It had started life as a kerosene model, but the previous owner had converted it to gas. A small can of propane screwed onto the bottom.
We soon noticed something strange. It didn’t seem to be producing a lot of heat, and what heat it did produce rose to the top of the cabin and stayed there. What was even stranger was the fact that the can of propane was collecting a coat of ice. If we stood up in the cabin, the air was luke-warm from the belly-button up, and freezing cold from the belly-button down. As the layer of ice on the can grew thicker, we shut the heater off, fearing that it was actually producing more cold than heat on average. Our bunks were below belly-button level, so we spent a very cold night aboard, having brought only light-weight sleeping bags with us.
One of the first jobs I did on that boat was to convert the Force 10 back to kerosene heat.
It was a fairly easy job once I’d bought the right tools for flaring the copper tubing and so on. The new burner put out a lot more heat and never tried to make ice, but the hot air still hung around above belly-button level until we bought a 12-volt fan and mounted it where a reading lamp used to be. That stirred the air up nicely, distributing warmth all over the cabin from head to toe.
But we rarely used that heater because the fan used electricity, and I was scared we might flatten the battery overnight and not be able to start the diesel engine on a cold morning.
I have learned over the years that very little is simple on a boat, and the less you have to go wrong the better off you are.
So we never had a heater on any other boat since. And our belly buttons have been very grateful.
Today’s Thought
What is true, simple and sincere is most congenial to man’s nature.
— Cicero, De Officiis
Tailpiece
“Who gave you that black eye?”
“My wife.”
"I thought she was out of town.”
“So did I.”