Daniel, I second the Delonghi's. I have now insulated my kayak area with 1" rigid foam and can keep it at about 70 degrees on the low setting of 3. It goes to 6. Its been in the low 40's at night the last few days. The heaters runs about $59.00. I got ours at Orchard. Here is a pic of the area. The walls and ceiling is now insulated. There is a small spark that occurs when the the thermostat kicks on and off so vent the varnish fumes as you deem safe.

John