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!

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.

Winterizing Your Pontoon Boat: The Newbie’s Guide


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 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 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
  • Safely cleans all interior surfaces with a matte finish
  • Contains sun blocking agents to preserve original appearance
  • Interior Detailer that will not leave behind a greasy appearance or feel
  • Improved, deeper cleaning formula that is safe to use on your interior car screens
  • Quickly and safely clean interior plastics, vinyl, leather, rubber, metal, and even LCD and navigation screens.Cleans & protects all interior surfaces

If you own a trailer—and 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 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
  • Designed with ergonomics in mind, the cushion grip handle improves comfort during cleaning. And you can hold the easy-to-pull spray trigger with minimal effort, reducing fatigue
  • Integrated ½-inch gallon detergent tank provides convenient on-board storage for cleaning detergents
  • Featuring a Generac OHV horizontal-shaft engine, the pump is well above the ground at the same level as the engine, which makes hose connections a snap
  • Designed with 10” never-flat wheels, maneuverability is easy, regardless of the terrain
  • Quick change nozzle tips 4 included (0-degree, 25-degree, 40-degree, soap) for tackling any job

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

The Engine

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 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.
  • Coats internal engine components to prevent corrosion
  • Displaces moisture from metal to protect engine
  • Lubricates cylinders to prevent cylinder damage (scuffing) at start up
  • For all 2-cycle and 4-cycle gasoline engines
  • Made in the U.S.A.

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).

Non-Toxic Anti-Freeze, 50F 6 Gallons
  • 6 Gallon Case Marine, RV, Pool Non Toxic Antifreeze
  • Safe for copper, brass and all types of plastic.
  • Non-toxic virgin propylene glycol formula.
  • Protects water systems & engines from freeze ups during storage.
  • Contains corrosion inhibitors to protect all metal engine components and seals.

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 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 and 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).

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: Add a few center poles underneath to keep air circulation. Otherwise, come spring—you’ll find a petri dish of mildew. These center support poles by Vico Marine (check price on Amazon) comes with an additional boat vent and base for support.

Vico Marine Support Pole (28" - 47") + Boat Vent 2 (G47A-1 BV2 BLK)
  • Vent and support your boat cover - up to 170lbs of pressure
  • Quick and easy installiation. Extends to 47" maximum.
  • Cam lock mechanism for easy adjustability
  • Poles made from premium anodized aluminum

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

TAYLOR MADE PRODUCTS 55741 Boat Cover Support System,Black
  • Boat cover support pole 28" -48"
  • 50' of 1" polypropylene webbing
  • Quick release adjuster buckles
  • Ideal for boats up to 23'
  • Creates a slope in your boat cover to prevent water from pooling or pocketing

Another method would be to invest in a dehumidifier like this DryWave 1000 AirDryer (check price on Amazon).

Ironwood Pacific Drywave 1000 Air Dryer
  • Gently warms the air to prevent condensationWorks in spaces up to 1,000 cubic feetTested for safe, continuous operationThermal cut off switch prevents overheating
  • 2 year warranty; Made in the USA

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 docking—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 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.