If my boat is on a lift, how do I determine which size Xtreme Heater is right for me?

Generally speaking, you should select a larger Xtreme Heater for boats stored on lifts. In most areas, the water does not reach freezing temperatures, which helps protect the boat. With the boat lifted out of the water, that benefit is lost and your boat will acclimate to the ambient air temperature.

Also, with your boat on a lift, the exhaust exit is exposed to the elements, and wind could drive cold air into the engine compartment.