When the crisp air starts to bite and the docks begin to empty, one truth remains: it’s time to winterize your boat. Whether you’re a seasoned captain or a first-time boat owner, proper winterization is the key to avoiding costly spring surprises.
At Grace Marine, we’ve seen it all—cracked blocks, seized engines, corroded wiring, and gel coat nightmares that could have easily been avoided with a little off-season love. This blog is your go-to guide for DIY boat winterization—plus when it’s best to call in the pros.
Let’s keep it simple:
Water expands when frozen.
Your engine, tanks, lines, and fittings do not like to expand.
Boom—expensive repairs.
Winterizing your boat protects your investment from freezing temperatures, moisture build-up, fuel degradation, and corrosion. It also keeps pests out, prolongs the life of your systems, and ensures you’re ready to launch when the first warm day hits.
Whether you store your boat in our Captains Quarters DryStack & Storage or at home, winter prep is a must.
Here’s a step-by-step checklist to get your boat buttoned up before winter hits hard:
Top off the fuel tank to minimize condensation.
Add marine-grade fuel stabilizer and run the engine for 10–15 minutes to circulate it.
Replace fuel/water separator if needed.
Change the oil and oil filter.
Flush the engine with fresh water.
Drain and replace gear oil in outboards and sterndrives.
Fog the engine (2-strokes especially) to prevent internal rust.
Drain and flush with antifreeze if applicable (inboards, sterndrives, some outboards).
Ensure raw water intake is closed or blocked off.
Disconnect and remove batteries.
Clean terminals, store in a dry location, and maintain charge with a trickle charger.
Wash the hull, decks, and upholstery.
Remove food, gear, and valuables.
Use moisture absorbers inside cabin/storage areas.
Plug exhaust ports and ventilation holes with steel wool or pest-proof covers.
Set traps or deterrents if storing in a garage or barn.
Use a breathable, properly fitted boat cover or shrink-wrap.
Avoid pooling water with support poles or framing systems.
Let’s be honest—some things are better left to certified technicians, especially when it comes to winterizing:
Inboard engines with complex cooling systems
Electronic diagnostics or system flushes
Repairs, upgrades, or seasonal maintenance you’ve been putting off
At Grace Marine, our factory-trained service team knows your boat inside and out—whether it's Yamaha, Mercury, MerCruiser, Crownline, Barletta, or Moomba. We’ll make sure it’s stored, serviced, and ready to perform on day one of next season.
💡 Schedule a winterization service or boat storage right from our Service Page or DryStack Storage Info.
Grace Marine proudly serves the boating community of:
Le Claire, Iowa
Davenport, Bettendorf
Moline, Rock Island, East Moline, IL
And all Mississippi River recreational boaters
Our winterization services and Captains Quarters DryStack are trusted by anglers, wakeboarders, and families across the Midwest.
Spots for winterization and storage fill up fast. Let us take the guesswork out of protecting your boat so you can enjoy your off-season stress-free—and your first trip next season worry-free.
🔧 Click here to schedule your winterization appointment
🧊 Explore our boat storage options here
📞 Or call us direct at (563) 289-5050
