I recently bought a Catalina 27 with an Atomic 4 inboard and have it in a slip in San Leandro (San Francisco Bay) The winters are pretty mild, get to below freezing maybe 10-20 times a winter. I want to continue sailing on nice days during the winter so I really don't want to winterize the engine each time I sail. I have a boat heater in the cabin to keep it dry and am wondering if that is enough? Should I leave the engine compartment door open? Should I look into an engine heater or heat tape? Any ideas from other SF Bay boaters. John