An old idea for keeping a cooling system from freezing, or helping an engine start in very cold weather is to put an incandescent light inside the hood. The bulb generates quite a bit of heat, and while it’s not very much like having the engine in a heated space, it does ward off freezing temperatures.
The weather has been unseasonably cold this fall and there are freeze warnings tonight and tomorrow. As Cay of Sea is still in the water and un-winterized, I’ve adopted this old method for keeping the engine above 32 degrees.
I don’t think there is much danger of damage from early morning freezes, as the water temperature is hovering around 50f. But I’d rather take conservative measures and not worry. I think the water and sanitation systems will be fine with temps near 32 overnight and daily warm-ups. There are just a couple days of this, and we’re back to 50s during the day, and low 40s over night.