Camco DIY Boat Winterizer The Camco DIY Boat Winterizer services inboard and outboard marine engines efficiently and quickly. The boat winterizer flushes and preps your boat engine for winter storage with only five gallons of antifreeze and a flusher of your choosing. You can conveniently winterize your engine directly on the trailer with the boat winterizers gravity flow system. Save time, money, and effort year after year. For front mounted raw water pump systems such as Volvo and others, use