
While late-season fishing is still going strong in many parts of the country, for others this is the time of the year to start thinking about tucking their boats in for the winter. Of course, you shouldn’t just park it in the shed for 4–6 months without at least some preparation.
Proper fuel stabilization and engine lubrication are the key components of any long-term boat storage plan. When done correctly, your boat will start up in the spring with a simple turn of the key. When done incorrectly, however, you may find yourself with a whole host of costly and time-consuming problems to deal with.
Whether this is your first off-season with a boat or you’re looking to not repeat the mistakes of the past, here are the three steps you should follow to properly winterize your boat’s fuel.
1. Plan out your final trip on the water
This first step is as much practical as it is just plain old good for the soul. You’ve no doubt spent countless hours out on the water this past year, and your loyal vessel deserves a fitting farewell for the season—not that you need an excuse for one last skip across the waves.
The “real” purpose of this voyage, however, is to burn through the remainder of your current fuel. If you’ve been routinely adding a fuel stabilizer throughout the season, then you’re a step ahead of the pack. If you haven’t, then this is a great time to start because you want that stabilized fuel to get completely distributed throughout the entire system.
2. Add in the best fuel stabilizer for boats
While the original Sea Foam Motor Treatment is a great option for stabilizing any engine’s fuel, Marine PRO is specifically formulated to provide everything a boat owner needs in a fuel system treatment.

Whatever fuel stabilizer you decide to go with, be sure to carefully read the instructions on the can before use. If you’re using Marine PRO, you’ll want to add 1 oz. for every 1 gallon of gas* on that final fill-up. A single can of Marine PRO can stabilize up to 20 gallons of fuel.
*Don’t worry if you exceed these amounts – Marine PRO only contains petroleum-based cleaning & lubricating ingredients. Marine PRO does NOT contain harsh chemicals, alcohol, or abrasive detergents that could harm your engine.
3. Run the engine to distribute the treated fuel
The last step is to work the fuel treatment through the entire fuel system. On your final outing, add a can or two to the fuel to make sure there’s enough time for the fuel treatment to make it through the entire fuel system and into the engine.
After about fifteen to twenty minutes of running, the treated fuel should have worked its way through the fuel line and fuel injectors (or carburetor), ensuring your system will fire up without issue in the spring when you need it.
Oh, and we should probably mention that Sea Foam Marine PRO can stabilize fuel for up to two years—not that you’d ever want to be off the water that long!
Sea Foam—the original marine fuel stabilizer
Sea Foam was born on the water. Unlike other fuel stabilizers on the market today, we got our start in the marine industry in 1942 and have been creating exceptional products to make boat owners’ lives easier ever since.
Shop our products today to learn why professional fishermen, hobbyists, and watercraft enthusiasts alike continue to reach for Sea Foam.