On Lake Champlain, where the ice gets 2-3 feet thick in the worst of winters, the old-timers used to cut the ice around the sidewheel steamboats by hand with big ice saws. Boxes were built around the sea chests and packed with manure, the latent heat was enough to keep them from freezing. In later years, we pumped vegetable oil into the sea chests to accomplish the same thing. John "Seahorse" Reply to: John@Camm.us Willy writes: I am seeing the first through hulls fracturing on the river. The ambient temp of the water around Vancouver is now low enough that it will not keep boats from freezing below water lines. We have not had to worry about this for few years and seeing a boat up to its gunnels in the water is not a nice picture.