Winterizing Your Pontoon Boat: The Newbie’s Guide

Winterizing Your Pontoon Boat: The Newbie’s Guide

It's been a fun boating season, but the colder months are here. It's important to protect your investment and learn how to winterize your pontoon boat.

For a newbie pontoon boat owner, the steps for winterizing can seem a bit daunting. Especially if you want to save money and do-it-yourself. Simply follow these basic tips for preventive maintenance, and you'll be able to protect your craft for many years of enjoyment.

As always, be sure to refer to your manufacturer's manual for your specific vessel.


Before you dive into it, give her a cleaning from bow to stern. Make sure to remove all unmounted accessories. This includes everything from fishing gear, depth finders, anchors and electronics to flotation devices and skis.

Not only will these items be protected from damage, but removing the clutter will help you move more swiftly through the following steps.

The only items left should be bolted down, including carpet! Wipe down seats with vinyl cleaner to remove all dirt, moisture and sunscreen. Don't use anything too harsh or soapy. Instead, use a protective polish such as this Meguiars interior detailer spray (check price on Amazon).

Meguiar's G13616EU Quik Interior Detailer Cleaner 473ml for a matt finish




If you own a trailer, before you pull anything out, follow these five essential tips. In addition, always check your tires, wheel bearings, lights and have a spare tire on hand.

After pulling your boat out of the water, you'll next want to focus on the exterior. You can use this excellent, affordable pressure washer (check price on Amazon) to clean the toons and focus on removing any build-up of barnacles and sediment.

This step in how to winterize a pontoon boat is especially important if you dock at a coastal marina or near salt water.

Generac 6922 2,800 PSI, 2.4 GPM, Gas Powered Pressure Washer





Lastly, it's important to protect your toons from dirt and apply polish to the aluminum.

The Engine

When you're learning how to winterize a pontoon boat, it's always good practice to consult your owner's manual for any specific instructions, but this goes double for your engine.

There are two types of engines to consider: Outboard and inboard/outboard.

Outboard Engine

For an outboard engine, you'll want to first disconnect the battery. Then, so that it doesn't collect rainwater, lower the engine. Most manufacturers, and this goes for both engine types, suggest fogging to lubricate the inside of the engine.

Inboard/Outboard Engine

Drain the engine block as specified by the boat manufacturer. Once again, fogging also goes for these engines. You can learn more about fogging oil with this well-rounded breakdown by Gold Eagle.

As they suggest, one of the top brands of fogging oil is by STA-BIL (check price on Amazon).


STA-BIL (22001) Fogging Oil - Stops Corrosion In Stored Engines - Lubricates And Protects Cylinders - Coats Internal Engine Components - For All 2 and 4 Cycle Engines, 12 oz.



The last step you'll want to do is add antifreeze. Drain the engine of coolant and replace with one that's Propylene Glycol based (check price on Amazon).

STAR BRITE Non-Toxic Anti-Freeze, 50F 6 Gallons




There are antifreeze brands that contain Ethylene Glycol, but most recommend Propylene. Additionally, Ethylene-based antifreeze can release harmful toxins into the water.

Fuel and Oil

You want your fuel tank to be at about three-quarters capacity. Although some recommend more, this is a happy medium for lowering condensation levels inside the tank.

Next, you'll want to add a fuel stabilizer.

Lastly, you'll want to switch off valves and seal exhaust ports. This last step in how to winterize a pontoon boat helps prevent any internal corrosion to the tank.

Now, replacing the oil and filters can be done during winterization or de-winterization. Check your owner's manual for the specifications of the oil viscosity.

Lower Unit

For both types of engines, you need to drain the lower unit oil. If you see a milky consistency, this means you're getting water inside. This needs to be addressed by your mechanic.

The Battery

One decision to make for the battery is if you wish to leave it on board or remove it for the season. If you go with removing it, you'll need to store it indoors in your garage or somewhere above freezing temperatures.

If you decide to leave the battery in instead (which some do if they leave their pontoon in water), you need to take an extra precaution: Disconnect the battery and connect it to a trickle charger (check price on Amazon).

Marinco 36082-12 8 Amp 12 V Dual Output Marine On-Board Battery Charger and Alternator Module




The trickle charger is a good investment anyway, as it's handy to have around when pontoon seasons rolls around again.

Storage and Covers

The last thing you want is to find a crack in your pontoon's hull. Whether you pull her out with a trailer or have a dock lift, removing your pontoon from the water to dry dock is truly going to protect your investment.

Hull repairs are labor intensive and can become quite costly. There are multiple cover manufacturers out there. Be sure to do some research to compare them to find what fits your needs. And make sure you order the right size.

Some recommend using a repellent to keep away mice and other critters from chewing holes in the cover.

If you prefer a natural repellent, mice avoid peppermint. Mix a solution of water and a few drops of peppermint oil and spray along the floor and any interior crevices. Plus, it'll give your boat a really fresh smell when you pull her out for next season.

Folding back the canvas cover from front to back, align the snaps and be sure the cover is taught, but not so tight it could rip. Another useful tip for how to winterize a pontoon boat: add a few boat cover support poles underneath to keep air circulation. Otherwise, come spring you'll find a petri dish of mildew. 

Featured Boat Care Product

      Boat Cover Support Poles

Check Price on Amazon - Better Boat's boat cover support pole includes a button snap rubber end, a mushroom top and a sturdy base. It extends from 23.5" to 56". Use with boat cover straps for a safe and supportive hold that will prevent rain, snow, ice and debris from ripping your boat cover.   

And for full support, you can't go wrong with this Taylor Boat Cover Support System (check price on Amazon)

Another method would be to invest in a dehumidifier like the Better Boat refillable dehumidifier container.

Although not necessarily crucial, one extra step would be to shrink wrap. Because your craft would be wrapped entirely in plastic (as opposed to only a canvas cover) it adds another level of security from the elements.

It protects against high winds, water leakage and even with indoor storage issues such as dust, insects and rodents. It's possible to purchase a shrink-wrap kit and DIY, but if you're a newbie and want it done right, it's best to go with a professional service.

Security and Theft

Vandalism can happen anywhere, from public facilities to your own private property, but it's easily prevented. Similar to latching windows and locking doors, there are cautionary steps and measures you can take to secure your pontoon.

The first items to be stolen would be electronics. Unlike an entire boat, it's incredibly easy for someone to rip out unless you've already dismounted them.

If your pontoon is being stored on land, mount the trailer on blocks and remove the tires. This will definitely keep your boat from being wheeled away. Another way to deter would be to purchase a tongue lock for the trailer.

One note to add on boat insurance: Basic property coverage plans only cover the theft of the boat and major equipment parts such as fuel tanks and motor engines. They don't cover accessories or anything that isn't permanently attached. Be sure to consult your policy for details or contact your agent for further clarity.


When winter's long gone and you're itching to drop the boat back in, you'll still need to do a spring boat inspection. Check for large damage first. Look for dents or leaks and, if you have any, tend immediately to those.

Look over your covers and bimini tops. You may find you need to repair your vinyl or canvas of a few tears or holes. Most canvas covers come with their own duffel, but before tucking it away, make sure it's fully dry.

Replace your accessories and reinstall electronics but don't forget to test them. You don't want to be in the water when you discover your GPS system's wires aren't thoroughly connected, or worse, has gone kaput.

And if it makes you happy, give her aluminum another polish.

Time for the Water Again!

Winterizing a pontoon boat takes some planning. If this is your first year of pontoon ownership, be sure to take inventory and order in the products you need to get the job done.

Come next year, you'll be an absolute pro at winterizing your boat! More so it takes time!

But in the end, you'll be very happy the day you remove the cover to a well-maintained pontoon boat.