- Drain engine, water cooling system, and ballast (if equipped) of fresh water. Fill with coolant if desired.
- Fill fuel tanks and add stabilizer to gasoline.
- Change oil and filter.
- Remove and/or disconnect batteries (or put batteries on a marine charger).
- Use a boat cover or shrink wrap your boat (if not stored indoors).
- Blow out heater and shower if equipped (added by David O.).
*It is highly recommended to take your boat to your dealer to winterize correctly as every boat is different. The procedure will vary on make and model.