If you see any cracks in your hull, these may be indicative of a more serious problem and should be evaluated by a professional. If you find blisters in the gelcoat on your hull, puncture them, drain out any water, and patch them with an epoxy-based filler like West System or West Marine Gelcoat Repair Kit., If you have scum and barnacles adhering to the bottom of your boat, you may wish to use a scraper to remove the barnacles and a pressure washer to blast off dirt and scum.If you choose to do this, be conscientious about local laws governing boat pressure washing procedures.You can prevent future scum buildup by treating the bottom of your boat with boat wax (such as 3M Marine Ultra Performance Paste Wax)., Use a gentle all-purpose cleanser to wipe down interior surfaces and get rid of grime. If necessary, vacuum and wash any carpets.If your boat has any interior vinyl components, treat them with a vinyl cleaning and protection solution like 3M Marine Vinyl Cleaner.
Remove any obvious mold and mildew with a mildew cleanser, such as Star brite Mildew Stain Remover.
 Remove whatever electronics you can and store them in a dry environment. Spray any exposed electronic fixtures with a moisture displacing lubricant, like Corrosion X or WD-40., Look for dented or bowed blades and widespread wear. Change damaged parts and perform needed repairs when winterizing your boat.
Check your hull for stress cracks and blisters.
Clean the bottom of your boat.
Clean the interior of your boat.
Protect your electronics and electronic fixtures.
Inspect your vessel's propeller and hub.
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