Winterizing Your Boat - Sailors for the Sea

Winterizing Your Boat

Properly storing your boat for the winter will ensure that you protect the environment and are ready for on-the-water fun come springtime! 

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Properly winterizing and storing your boat will help prevent damage and make sure you are ready for on-the-water fun in the spring. Consult your manufacturers’ manuals and service guides for specific winterizing, flushing and maintenance instructions before you begin. Plan ahead, create a checklist (see below) and gather all the items you will need to winterize and store your boat.

winterizing, haul out, boat hauled out


  • Fill fuel tanks, add stabilizer, and change fuel filters and separators.
  • Change oil and filter.
  • Check coolant level in freshwater-cooling system and add coolant as necessary.
  • Run antifreeze through raw-water-cooling system. Use propylene glycol antifreeze (orange-pink color) as it is non-toxic.
  • Dispose of and/or recycle waste oils, engine coolants and hazardous materials properly.


  • Fill fuel tanks and add stabilizer.
  • Drain gear case and add eco-friendly lubricant.
  • Flush engine with freshwater using an “ear-muff’ flushing device.


  • If you take your batteries home, store them in a cool, dry place such as your basement and put them on a trickle marine charger.
  • If you leave your batteries aboard, make sure battery cable connections are tight and free of corrosion, and hook batteries up to a marine charger or leave them unplugged and charge them completely at least once a month.

Below Deck

  • Clean and dry bilges, and verify bilge pump operates properly.
  • Pump out holding tank and add propylene glycol antifreeze to the head.
  • Drain all systems that use water (water heater, freshwater system, shower sump, etc.) and replace with propylene glycol antifreeze as appropriate.
  • Remove all food and beverages, and clean food particles that may tempt winter critters. 
  • Secure all ports and hatches.

Store in the Water

  • Close all seacocks except for cockpit drains and plug exhaust ports.
  • Check docklines, chafe guards and fenders for proper placement.
  • Tie off tiller or steering wheel.


  • Custom-made canvas or synthetic covers are the best at protecting your boat from the elements, are reusable, and allow for air circulation (prevents mildew buildup). Using a canvas cover can also save you money in the long run
  • Shrinkwrap covers are effective at keeping rain and snow out, but susceptible to moisture buildup. Professionals should shrinkwrap your boat as it is very easy to damage your boat and/or ignite the shrinkwrap. Recycle your shrinkwrap!
  • If you use a different type of covering, make sure that it is water/snow proof, and that there is adequate air circulation.

Did you know?

  • Analyzing over ten years of freeze claims, BoatU.S. Marine Insurance found that more than 3/4 of the claims involved cracks in the engine block or the exhaust manifolds that occurred because water remained in the engine or cooling system during a hard freeze.