My neighbor learned the hard way that boats do not hibernate. He parked his runabout in the garage in October, patted it like a dog, and found a corroded mess in April. The starter motor alone cost him a weekend and a stack of cash.

Winterizing a boat is not glamorous, but it is mostly simple, and almost all of it happens in one afternoon before the cold sets in.

The Fuel Is the First Thing

Gasoline goes bad, and bad gas is the number one reason boats do not start in spring. The fix is to stabilize it before it sits:

1. Add fuel stabilizer to the tank according to the bottle’s directions.
2. Run the engine for ten minutes so the treated fuel reaches the carburetor or injectors.
3. Top off the tank. A full tank leaves less room for condensation, which is the other fuel killer.

Skipping this step is how you end up draining gummy fuel and rebuilding a carburetor in the spring. I have seen it happen to three different people, and all three said the same thing: it took one afternoon in fall to prevent a month of spring misery.

Drain What Should Be Drained

Different boats need different winter prep, but the general list is:

• Lower unit oil: Change it in fall. Old oil can hold water that freezes and cracks the housing over winter.
• Fresh water system: Drain it completely or fill with antifreeze made for boats. Frozen water expands and splits hoses and tanks.
• Livewell and bilge: Pump them dry and leave the drains open.
• Engine block (inboards): Drain the cooling system or run antifreeze through it. This is the step people skip and regret most.

Fog the Engine and Fog the Worries

Fogging oil is sprayed into the intake while the engine runs, coating the cylinders so they do not rust over the winter. It takes two minutes and it is cheap insurance. If you have an outboard, tilt it down so water drains out of the lower unit, then fog it and tilt it back up.

One more thing: disconnect the battery and put it on a tender. A battery that sits dead all winter is usually a battery you buy in spring.

Cover It Like You Mean It

A cover is not just for looks. A good cover keeps out rain, snow, leaves, and the critters that love nesting in a warm boat. Make sure it is strapped down tight enough that snow does not pool in the middle. Throw a few moisture absorbing packs inside too, because trapped humidity causes mildew faster than any leak.

Write It Down

The best winterizing tip I can give is a checklist on paper. When the boat is in the water in July, you will not remember what you did in October. I keep mine in the glove box with the registration, and every fall I go through it line by line. Takes an afternoon, saves a spring.

📋 Quick Summary: Stabilize the fuel and run it through the engine, change lower unit oil, drain water systems, fog the cylinders, disconnect the battery, and cover the boat properly. One fall afternoon prevents a month of spring repairs.