I installed one of these last month in conjunction with a wall-mounted programmable thermostat, in a bathroom that didn't have it's own heat. It's an old house and this particular bathroom is off the kitchen. It used to be a pantry, and it has two outside walls. In winter it would sometimes seem like an outdoor space . The act of sitting in that bathroom could be an adventure if the door hadn't been left at least partially open to allow heat from the rest of the house. Having this heat has made it "civilized".

Works great! Something like this might also work beneath the settee on a boat, and it could be mounted a bit higher in the settee's wall if the turn of the bilge restricts depth. It can be set for 750 or 1500w at either 120 or 240v, and it has mounting room for an internal thermostat on the face plate.