Summerizing as so many people often do is no substitute for WINTERIZATION. And  just draining the water from the engine is NOT winterizing. Our winterization is a 50 point service taking care of ALL crucial points. Even if you are mechanically inclined, dont take on the job yourself and expect good thorough results. You are guaranteed to miss something plus you dont have all the specialty tools needed. Eliminate your concerns by taking it to a REPUTABLE dealer. So many dealers are not so ask questions as to how entailed their service is. Even though it may coat a little more, it's so much cheaper than what it may cost later. You can forget you own a boat during the winter after a great service.