The 1000W version of this boat engine heater is ideal for very cold climates, such as the North East or Great Lakes Region. If you have a dual motor engine, you'll also need a 1000W unit. If there's any other additional equipment in the compartment, including tanks or generators, we suggest two 1000W units. And of course, like all BoatSafe Heaters, it combines safety with efficiency, and security. That means you can extend the use of your boat for days and even months of additional use in the cooler weather. Designed to turn on at 45 degrees and shut off at 55 degrees.