Lake Erie winters do not forgive skipped steps. Water expands about 9% when it freezes, and it finds its way into engine blocks, water systems, and gelcoat cracks, then does its damage silently until spring.
This is the working checklist we recommend to owners from Catawba to Mentor. The engine steps vary by motor type, so treat that section as a map, not a substitute for your engine manual.
Engine and drivetrain
- Stabilize the fuel and run the engine long enough to circulate it.
- Drain cooling water completely. On inboards and sterndrives, flush and fill with marine antifreeze rated well below your coldest expected temperature.
- Outboards: tilt down so water drains, fog the cylinders per your manual, and change lower unit gear oil while any water contamination is visible.
- Change the engine oil before storage, not after. Used oil holds acids and moisture all winter.
Water systems and plumbing
- Drain the freshwater tank, water heater, and all lines, then run non-toxic antifreeze through every faucet and the washdown pump.
- Pump out the head and holding tank, then winterize per the manufacturer.
- Pull the drain plug and store it somewhere you will find it in April.
Detail before you cover it
The step most owners skip is the one we care most about: go into storage clean and protected. Scum lines, salt, and organic grime left on gelcoat all winter etch in and oxidize, which turns a spring wash into a spring compound job.
Wash the hull and deck, deal with the waterline, and get a coat of protection on the gelcoat. Clean and dry the interior, prop cushions up for airflow, and leave a moisture absorber aboard. Mildew grows in closed, damp cabins, and vinyl seats are its favorite meal.
What winterizing costs
Cost depends almost entirely on engine type and count: a single outboard is a much smaller job than twin inboards with a generator and full plumbing. DIY costs you antifreeze, oil, and an afternoon; a pro service costs more but comes with someone to call if a block cracks anyway.
Whichever way you go, do it before the first hard freeze, not after the forecast announces it.
Spring de-winterizing
In spring, reverse it: reinstall the plug first, reconnect batteries, flush the antifreeze, check the impeller before extended running, and inspect every hose clamp the cold may have loosened. Then start the season with a proper detail, and you will fight the water instead of last year's grime.