I have relied on XTreme heaters over the years and continue to see how well they perform on both our larger houseboat and bow rider. Being in GA we don’t have the constant concerns with freezing temps but during extended cold waves in January one large XTreme heater is doing the job. I monitor temp remotely and the temp trend I see in my houseboat validates the heater never allowing this relatively large bilge to fall below 42F. And the nights have dipped into the 20s of late. Even more impressive performance in my 26ft bow rider. Great Product!!