9 Winter Boat Storage Tips

Updated: Oct. 27, 2023

Winter is coming. Is your boat ready? Protect your boat and get back on the water fast next spring with these winter boat storage tips.

Boats are fun, but they come with a reputation. “Boats are holes in the water into which you throw money” is a common adage. Or, as a boat-owning member of my family likes to say, “Don’t buy a boat, make a friend who has a boat.”

If you’re the friend who owns the boat, it’s tough to disagree, especially when it comes time to store it for the winter.

Boat storage ideas range from dry dock to keeping it in a slip all winter. The best choice for you depends on where you live and what you can afford. However you decide to winterize your boat, make your plan well in advance of winter.

Below are some universal tips for storing boats. Inboards and outboards have slightly different requirements, so consult your boat and motor manuals before beginning. If you do it right, you’ll be on the water in no time next spring.

Choose a Storage Option

If you live in South Florida, your boat storage options differ than those in Minnesota or Michigan. Cost, convenience and the type of boat you own play a role in your choice, too.

Large sailboats can’t be stored indoors without dismantling the mast. Pontoon boat covers must be supported in the middle to allow water to slide off, or heavy snowmelt will turn your deck into a swimming pool.

Even if you store your boat indoors, winterizing your boat motor is a must. Check with your storage facility; many marinas offer a package deal.

Here are your options for winter boat storage.

  • Leave it in the water: In warm climates and calm waters, many people keep their boat in their slip year-round. Check on your boat weekly during the winter. If it develops a leak or a storm comes through, come spring you could find your boat at the bottom of the lake or ocean.
  • Keep it on a lift: A boat lift prevents waves from banging your craft around and keeps the hull clean and barnacle-free, but they’re expensive to install.
  • Trailer your boat: If you own a trailer, cover your boat and keep it in your garage, yard or self-storage facility. It’s inexpensive and you can access your boat all winter.
  • Store your boat outside at a boatyard: Blocking your boat (i.e. storing it on dry land without a trailer) and securing it in a boatyard is popular and more affordable than indoor storage. This is often the choice for really large boats and sailboats.
  • Dry stack your boat: Many marinas will pick up your boat with a forklift and stack it with other boats in a climate-controlled storage facility. This is the most expensive option.

Clean Your Boat

You never want to clean your boat when you’re ready to take off in the spring. Over the winter, dirt and grime left behind from boating season can turn into mold or attract pests.

Before you close up your boat for the winter, scrub the decks and treat seats and wood trim to prevent moisture intrusion. Remove life jackets, towels and other porous materials from under seats and storage hulls.

P.S. Here’s how to wax a boat and get it shining like new.

Fill Up the Tank

Air left in the fuel tank expands and contracts during the winter, and vents draw in moisture. Leave a tiny bit of space for that expansion and contraction, but not enough so moisture accumulates and condenses inside the tank.

Fuel containing ethanol can actually absorb moisture and break down over the winter, leaving you with a separated, sludgy mess come springtime. Top off the tank and add a stabilizer (see the next tip) before storing your boat.

Add a Fuel Stabilizer

Fuel stabilizers prevent oxidation of gasoline stored for extended periods. Gasoline is a volatile compound of different chemicals, and over time it breaks down with exposure to air and moisture. Today’s ethanol-based fuels are particularly vulnerable.

When storing boats for the winter, add a fuel stabilizer like Sta-Bil Storage, which keeps fuel fresh for up to two years. Check the instructions on the package and add the proper amount based on the size of your fuel tank.

Change the Oil

Motor oil lubricates the engine parts and crankcase and collects byproducts of combustion. Before you put your boat away for winter, change the oil and filter to prevent rust and corrosion from settling in.

Marine oil contains special anti-corrosion ingredients that regular motor oil doesn’t have, so choose a high-quality marine oil instead of something for your car you have on hand.

Protect the Engine Block

Boat motors, like car engines, have a “block,” the metal housing containing the internal components. Before winter, the block must be drained of water (boat motors are water-cooled). If not, freezing and expansion can crack the block and ruin the motor.

In addition to draining, it’s smart to protect the boat motor with antifreeze. Never use regular automotive antifreeze (aka ethylene glycol) to winterize a boat motor, since it’s toxic to marine life. Instead, look for marine antifreeze made from propylene glycol, specifically intended for marine and RV applications.

Remove and Charge Battery

A dead battery at the beginning of boating season is a real drag. Instead of being out on the water, you’re pulling the battery out and charging it. Or worse, driving to the marina to buy another one.

Before storing your boat for the winter, take out the battery and store it away from freezing temps. Give it a full charge before storage, and charge it again once a month. Or put the battery on a trickle charger for the winter.

Change the Gear Lube

The lower unit in your outboard motor has a lubricant that should be drained and refilled before storing your boat for winter. Have a drain pan handy before you start. Check the O-rings on the drain plug and the vent to make sure you don’t need to replace them before storage.

Some gear lube, like this one by Mercury Marine, comes with a pump for easy refilling after draining. Or purchase a pump separately.

Cover Your Boat

No matter where you store your boat, cover it to keep out mice and other vermin and protect it from the elements. (Indoor storage facilities have sprinkler systems and dust.) Cover options range from simple tarps with grommets to custom covers made to fit the specific dimensions of your boat. Shrink wrapping is another popular cover option.

All boat covers should have ventilation to prevent mold and mildew. If your boat is covered and accessible, open it up occasionally during the winter, weather permitting. Find out why you should have boat insurance.