It was sooo cold at the marina this weekend the water froze and snow was accumulating on top.
We had every heater pumping out as hard as they could. I have found that when it gets very cold our best heating combo is 1 Caframo in each bedroom and a 1 radiator style in the salon. This combo keeps us a pretty toasty 65 degrees :) I know it doesn't sound warm enough for the house dweller, but on a boat, this is high heat in the middle of winter :)
Stay warm maties! And enjoy the winter living aboard your boat!
I have included a link here to the Caframo Heaters so you can see the heaters that we swear by on our boat
http://www.caframo.com/marine/marine_products_heaters.php