Storing a Boat Outside in The Winter | 7 Winter Boat Storage Tips

Winter boat storage requires careful preparation to keep your boat protected from snow, wind, rain, ice, and other harsh conditions. For boaters without access to indoor storage, outdoor winterization is possible with proper precautions. Follow these 7 key tips for safe DIY outdoor boat storage this winter.

1. Choose a Strategic Location

Choosing the right outdoor location is the first critical step. The spot should be elevated, with good drainage and no possibility of water pooling around the boat. Avoid low spots or depressions in the ground that can collect rain or meltwater. The boat should be on a hard paved surface rather than dirt, sand, or grass that can erode or sink over time.

Concrete, asphalt or gravel are ideal surfaces. The ground should be free of rocks, sticks, and other debris that could damage the hull. Ensure there is plenty of clearance around the boat for removing and replacing the cover. Also, consider checking local regulations - some municipalities prohibit parking boats in front yards or on streets.

Ideally, find a location that is sheltered from strong winds and extreme weather. Position the boat if possible so the prevailing winds hit the stern rather than broadside. Avoid parking under trees where falling leaves, sap, fruits, and branches can accumulate on the boat cover. Select a spot that will allow you to easily access your boat all winter long.

2. Clean the Boat Thoroughly

Before winterizing, do a deep clean from bow to stern. Remove all debris, leaves, dirt, and grime accumulated over the boating season. Wash off the salt, bird droppings, and water stains. Pay particular attention to the bilge - pump out any standing water and use a bilge cleaner to dissolve grime and oils. A Shop-Vac is perfect for sucking up debris in tight spaces. Anything left on surfaces can promote mold/mildew growth when moisture gets trapped under the cover.

Clean upholstery, carpeting, and drapes with marine carpet shampoo or an all-purpose boat soap. Wipe down vinyl and leather. Remove the canvas and clean it underneath. A sparkling clean interior will prevent musty smells come springtime. As a final step, thoroughly wash the exterior hull, decks, rails, and cockpit. Consider applying a coat of UV protective wax which seals in shine and repels contaminants over the winter.

3. Change All Fluids

One of the most crucial steps is changing all old engine fluids to fresh fluids better suited for cold temperatures.

Start by draining old motor oil completely and replacing it with new oil that matches your engine specifications. Follow with a fresh oil filter. Old oil contains acids, combustion byproducts, and contamination that can corrode engine components if left unchanged for months.

Next, drain antifreeze from the closed cooling system. Refill with a 50/50 mix of new antifreeze and distilled water. Check that coolant provides adequate freeze protection down to the coldest expected winter temperatures in your area.

Replace the lower unit oil or outboard gear lube to get rid of condensation and metal shavings. Use marine-grade winter weight gear lube suitable for inboard or outboard lower units.

Top off fuel tanks with treated fuel and add a fuel stabilizer. Ethanol-treated fuel prevents gumming and corrosion issues. Stabilizers prevent fuel breakdown over long storage times. Condensing water in tanks also leads to problems.

4. Fog the Engine

Fogging oils protect internal engine parts from rust and corrosion. Start by completely draining water from seawater cooling systems, raw water pumps, and exhaust manifolds. Remove spark plugs and spray a fogging agent into each cylinder while turning over the engine. Fogging fluid coats cylinder walls, piston tops, valves, and rings with a protective film.

For inboards, fog via oil squirters if equipped. Outboards can be fogged using a fogging kit attached to the air intake. Run the engine at fast idle while spraying the fogging agent until it stalls out. Spray any remaining fluid into the carburetor or intake. The excess oil will be burned off next season during the recommissioning process.

Once fogged, disconnect and remove onboard batteries. Clean terminals and store batteries properly on land. Shut off fuel supply valves and detach fuel lines.

5. Custom Fitted Storage Cover

Investing in a high-quality storage cover tailored specifically for your boat is a wise idea. Unlike tarps, fitted boat covers are secured tightly to the rails and tie-downs to create a tight seal. The cover should be made from heavy-duty 600 denier marine grade canvas, polyester, or vinyl. Reinforced seams prevent tears and rips. Elastic hem cords keep the cover taut around the gunnels.

Quality covers feature venting to allow air circulation under the cover. Vents prevent condensation buildup and moisture that promotes mold growth. But vents should have screens to keep pests out. Storage covers also include strong integrated straps that fasten under the hull. Proper cinched straps keep the cover securely in place even through high winds, storms, and heavy snow loads.

Look for covers with UV inhibitors that prevent sun damage to the gel coat. Dark colors should be avoided since they absorb rather than reflect heat. Light colors are cooler. Getting a cover with an adequate waterproof rating keeps rain, melting snow, and ice from getting to your boat. Take time to properly fit the cover and adjust tie-downs for optimal protection.

6. Use Stands and Blocking

Boat stands and blocks prevent excessive pressure on the hull which can cause dents, cracks, and distortions over months of storage. Stands raise the boat to distribute weight evenly across the keel rather than concentrated in the center. Full-length keel rollers are ideal for proper support.

For boats stored on trailers, ensure the weight is properly supported. Shore up under axles and wheels to prevent flat spots on tires. Place blocking strategically under heavy accessories like motors to prevent sagging. Support areas where hardware mounts to the hull are high-stress.

Side blocks positioned along the gunnels and rails take pressure off the sides of the hull. Side stands are available that keep the boat perfectly level while preventing tipping or shifting. Proper proactive blocking avoids major repairs.

7. Install an Air Purifier

The enclosed space under the storage cover traps moisture from condensation and precipitation. This moist environment allows mold, mildew, and musty odors to develop, especially where dirt or spills are missed in cleaning. Prevent this with Airlock™ Boat Air Purifier which actively attacks microbes, allergens, and odors in the air before they take hold.

This compact unit uses advanced ionization technology to create millions of charged ions that alter contaminants and render them harmless. Installation takes only minutes - just mount it in an enclosed area and plug it into the boat's 12V power or a standalone battery. The rugged aluminum housing and marine-grade construction hold up to damp enclosed conditions all winter long.

Adjust the purge cycle timer to run as often as needed. Airlock™ cleans a full 800 square feet, handling even large cabin interiors. It requires no maintenance or replacement filters. Airlock™ Boat Air Purifier provides peace of mind your boat will stay fresh and dry until spring commissioning.

It is essential to ready your boat for the winter, doesn't matter you plan to store it indoors or outdoors.


Storing your boat outside over the winter months requires careful preparation and vigilance to protect your boat from snow, ice, pests, and temperature swings. While indoor storage is ideal, often boat owners must store their boats outside due to limited space or high costs.

Take the proper steps to winterize and store the boat for optimal protection. Invest in a high-quality cover secured tightly to the rails to seal out moisture that leads to mold and mildew growth. 

Use stands and blocking to properly distribute weight and prevent hull damage. Regularly inspect your stored boat and keep up with maintenance during the winter months. With proper precautions, you can safely store your boat outside and have it primed for launch day when warmer weather returns.

Taking the time to winterize and store your boat correctly protects your investment and prepares your boat for many more years of smooth sailing.

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