I head my boat with an oil-filled (airworks) heater in the v-berth, and a blowy cafrano heater in the saloon. they've both survived a few winters now, and don't seem to be having any problems yet. For a while, I had a pair of black&decker heaters largely because I could generally expect them to fail before their warranty expired, ensuring that I could maintain a continuous stream of new heaters, but got tired of dealing with that period of time between a heater failing and my getting a replacement.