Boat Winterization Checklist


Imagine that your boat is in pristine condition.
Now imagine having to junk that same boat one season later.


Is that possible?


What could ruin your pride and joy so quickly?


Failure to winterize.


When it comes to winterizing, it’s common for boat owners to skimp. But many boat owners simply aren’t aware of the compounding damage that comes from not winterizing their boats.


Ruined upholstery, electrical or battery damage, and even a cracked engine block are all consequences of poor maintenance. Shoddy maintenance and half measures do damage too, taking years off your boat, engine and components.

Our cleaning and maintenance checklist will help you keep your boat going for years to come.


Taking a few protective steps at the end of each season ensures that you and your boat are ready to get back on the water when it’s time.


Something to keep in mind though, winterizing isn’t going to be a priority everywhere. If you live in a warmer part of the country, maintenance requirements are obviously different.


On the other hand, if you live in parts of the country where weather extremes are pretty common you’ll want to save this checklist. Use this checklist accordingly to ensure your boat is protected.

Winterize your boat: The exterior


  1. Install a de-icing device if you store your boat in the water.
  2. Wash the motor and hull. Work to remove stains, scum, dirt and debris.
  3. Inspect your propeller and look for damage. It’s a good idea to service or replace your propeller at the end of the season when you’re not using your boat.
  4. If it’s not damaged, clean the propeller shaft and apply a protective coat of grease.
  5. Use a fiberglass cleaner to remove algae, rust, mildew and waterline stains from your exterior.
  6. Polish your boat and painted surfaces with a fresh coat of boat wax.
  7. Cover your boat with a breathable cover. Ideally you’ll want a custom cover that prevents UV rays from breaking down hoses, carpets and upholstery. Poly-cotton covers breath better than polyester but they aren’t as strong and don’t wear as well. When in doubt, go for quality.
  8. Properly covered boats stay drier. But covering also reduces the likelihood of your boat developing stress cracks and gelcoat crazing from water freezing and thawing on the decks.
  9. Once your boat is covered make sure there’s enough room for air circulation.
  10. Consider adding a tarp as well, as this increases the life of your cover, decreasing weather and wear. Choose a tarp that’s longer and wider than your boat.
  11. If you’ve got a sailboat, remove the sails. Take them home for a good cleaning and repair so they’re ready for next season.
  12. Consider unstepping your mast.
  13. Remove all bimini tops and canvas and store them at home or in a cool dry place. This gives you the chance to repair them and reduces any weathering in the off season.

Winterize your boat: The engine


  1. Look for broken or missing fasteners on your motor. Tighten or replace as needed.
  2. Run the engine to warm it up, then change the oil (crankcase and gear case) while the engine is still warm. Run it again to make sure the oil cycles throughout the power head.
  3. Change your oil filters.
  4. Flush your engine with water then drain it out.
  5. Once you’ve finished, run antifreeze through the engine block and manifolds.
  6. If you’ve got a fuel injected motor you’ll want to drain the vapor separator tank.
  7. For carbureted outboard motors, you’ll want to drain the carburetor float bowls.
  8. Change the transmission fluid.
  9. Replace your spark plugs then…
  10. Spray fogging fluid in to each of your carburetors, throttle body throats and spark plug ports to fog the engine.
  11. Remove raw water pump hoses.
  12. Lubricate the boat and motor completely. Wipe things down with a little fogging oil or WD-40.
  13. Add grease to the external engine fittings.
  14. Apply anti corrosion film to the external engine parts.

Winterize your boat: Electrical


  1. Verify that all wiring and connections are undamaged. Repair or replace anything that’s been damaged.
  2. Take out and store boat batteries. Be sure to charge them every 3 to 4 weeks.

Winterize your boat: Fuel systems


  1. Fill your fuel tanks to avoid condensation/water build up.
  2. Add fuel stabilizer to your fuel tanks.
  3. Change the fuel filter(s) and water separator(s).
  4. Drain attached fuel lines and move portable fuel tanks to a well ventilated area. Empty plastic tanks and top off metal tanks.

Winterize your boat: The interior


  1. Clean drawers and lockers out.
  2. Run a dehumidifier in your cabin (or enclosed areas) to reduce mold and mildew growth.
  3. Take fabrics, pillows, cushions and bedding out during the off season. Store them in a cool, climate controlled environment.
  4. Clean bilges with bilge cleaner and dry.
  5. Spray bilges with a moisture displacing lubricant; add a little antifreeze so any leftover water doesn’t freeze.
  6. Unplug the bilge drain. Put the plug somewhere safe so you can’t miss it when you’re ready for next season.
  7. Remove electronics, lines, PFF, fire extinguishers, flares, etc. Check, clean and service these items in the off season.

Winterize your boat: Boat storage


If you’re storing your boat on a trailer…


  1. Support your trailer by placing it on stands or blocks so the wheels are supported off the ground.
  2. Make sure the bow is higher than the stern so rainwater and snow drains properly.
  3. Remove trailer wheels, then clean and repack wheel bearings as needed.
  4. Check your tires for wear or cracking on the sidewalls.
  5. Verify that the electrical and wiring is working properly.
  6. Clean your trailer thoroughly, then repaint any chipped or rusting areas.
  7. Check the rollers and bunks for wear, replace anything that shows signs of wear.


If you’re storing your boat on jack stands…


  1. Make sure all jack stands are positioned on the bulk heads. Make sure your jack stands are chained together to prevent slippage.
  2. If you’ve got a sailboat the keel should be blocked to support most of the boat weight.
  3. Put plywood pads under your jack stands so they don’t sink when the ground thaws in the spring.
  4. DO NOT tie your tarp or cover to the jack stand. That tarp or cover acts like a sail when it’s windy and can blow the jack stand out from under your boat.


If you’re storing your boat in the water…


  1. Close all seacocks.
  2. Verify that your stuffing box is leak free.
  3. Make sure your boat is properly tied off and you’ve got chafe protection on your lines.
  4. Use de-icers to keep water circulating around your boat. This reduces the chance that the fiberglass will be damaged from water soaking or freeze in.


Follow the steps we’ve outlined and you’ll be able to enjoy your boat for years to come.

Is all of this preparation necessary?


If you’re looking to extend the life of your boat dramatically, then yes. Following this guide enables you to take the steps you need to protect your investment.


I didn’t do half this stuff and my boat is fine


Harsh weather conditions can reduce the life of your boat dramatically. If your boat is functional it’s easy to assume that everything’s fine. But it’s compounding that causes the problems. A little bit of damage here and there compounds over time, increasing the amount of wear and damage on your boat.

What if this triples my maintenance costs?


Proper maintenance costs a little bit more upfront but saves you thousands over time. Winterizing your boat is easy when you’ve got a solid plan and the right
cleaning supplies. It’s also cheaper to winterize your boat than it is to pay for major repairs. This checklist reduces, and in some cases, eliminates, major repairs.


This keeps you and your boat on the water, in tip-top condition.

Winterize and you’ll keep your boat going for years to come.


Boat maintenance doesn’t have to be an expensive or time consuming project. Follow our winterize checklist and you’ll avoid the hazards and potential damage that comes with the off-season.

Leave a Reply

All products proudly made in the usa

Download Catalog