Pontoons make up a big share of what comes into storage across Muskoka lakes -- they are the family boat of cottage country. They also have specific storage needs that differ from a V-hull runabout. Get the prep right and they come out in spring in the same condition they went in. Get it wrong and you are replacing deck furniture, dealing with tube corrosion, or chasing interior mold.

The aluminum tube issue

Pontoon logs (the aluminum tubes that provide flotation) do not need winterizing the way an engine block does, but they do accumulate water inside if the drain plugs are not removed. Most pontoons have drain plugs at the rear of each tube. Pull them before storage so any water that entered during the season drains out. Aluminum that sits with water inside through a freeze-thaw cycle can develop corrosion at the seams and, in worst cases, stress cracks where ice expands.

After draining, inspect the tubes for any dents, scratches through the paint, or marks from dock hardware. Bare aluminum exposed to air over winter will form an oxide layer, which is actually protective, but deep scratches into the tube wall benefit from a wipe of aluminum protectant before storage.

Deck and furniture prep

Pontoon furniture -- the wraparound seating, captain's chairs, and lounge sections -- is among the most expensive components on the boat and among the most vulnerable to moisture and UV damage over a Muskoka winter. Options for protection:

  • Store cushions separately: If the cushions can be unzipped and removed, bring them home or store them in a clean dry space at the cottage. A winter of moisture cycling inside a shrink wrap tent is hard on foam and fabric, even with ventilation.
  • Leave cushions on and wrap properly: If removing cushions is not practical, ensure the shrink wrap installation includes at least one forward and one rear vent to manage condensation. A properly ventilated wrap is significantly better for cushions than an unventilated one.
  • Remove portable electronics: Fish finders, chart plotters, and portable speakers should come off the boat for winter. The temperature swings inside a wrapped boat -- from minus-25 in January to plus-20 on a sunny March afternoon -- are hard on electronics even when they are off.

Shrink wrapping a pontoon

Pontoons present a specific challenge for shrink wrap because of their flat deck profile. Unlike a V-hull with a naturally peaked cabin or windshield, a pontoon's deck is nearly flat, which means snow accumulates and the wrap can sag under load without adequate support framing.

A proper pontoon wrap includes a center ridge pole or a series of support straps across the deck to create a peaked profile that sheds snow. Without this, even 7-mil film is at risk of splitting under a heavy Muskoka wet snowfall. We install support framing on all pontoon wraps as standard -- it is not an optional add-on.

Blocking and support

Pontoons should be supported on their cross-members (the frame rails that connect the two tubes), not on the tubes themselves. Blocking placed under the tubes can deform the aluminum at the contact point over a seven-month storage period. We use padded blocking at the frame rail positions to distribute the weight correctly.

Make sure the trailer tongue jack is in good condition before storage. A pontoon left on a trailer with a leaking or failing jack can shift or drop over winter, putting the frame under stress. If the trailer will be stored with the boat, set the tongue jack on a block of wood to prevent the foot from sinking into soft ground.

Engine winterization is the same as any outboard

If your pontoon has an outboard engine -- most do -- the winterization process is identical to any other outboard: flush, fog, lower unit oil change, fuel stabilizer, battery removal. See our outboard winterization post for the full breakdown. Pontoon sterndrives and inboards follow the same winterization process as any sterndrive or inboard.