How to Winterize Your Boat
Photo of a Boat Yard taken by Matthew Henry
How to winterize your boat’s interior
For this section we will not be talking about how to winterize your boat's motor or anything in the hull, that will be later. The first step is to remove everything possible from all storage compartments on your boat. This includes any food, life jackets, electronics, and fire extinguishers or any other safety equipment that could be damaged. You should also open lockers and other areas for ventilation to prevent mildew or mold from forming.
How to Clean Your Boat For Winter
Cleaning your boat is a very important part of winterizing your boat and protecting your investment. To clean your boat it is important to remove anything that could stain, first, salt and grime. Additionally, if you are washing your boat’s fiberglass it is smart to use a pH-neutral boat soap that won't strip away your wax. Make sure to wash your boat's hull, deck, and interior thoroughly, because anything that is left behind can cause corrosion and mold during storage. And lastly make sure you let everything dry completely before putting anything away to prevent mildew.
How to Winterize Your Boat Motor
Arguably one of the most important parts of winterizing any boat is to winterize the motor. This may seem very overwhelming, especially for those who are doing it for the first time, so we have decided to break it down into two separate categories for simplicity. These steps are crucial for every boat engine before putting it away for the winter.
For inboard motors-
Flush with fresh water: For this you want to connect a garden hose to the engine's raw water intake or a dedicated flushing port, start the engine at idle, and let it run for 5 to 10 minutes to get the fresh water through the cooling system before shutting it down.
Add antifreeze: After flushing out the old water, you'll want to circulate non-toxic marine antifreeze through the cooling system.
Change the oil and filter: Old oil can contain moisture and acids that corrode engine parts so it is very important to change it if you're going to store it for a long time such as for winter.
Add fuel stabilizer: You add the stabilizer to your fuel tank and let the boat run for about 10 to 15 minutes so that the stabilizer has enough time to flow through the engine. You should add 1 ounce of stabilizer for every 2.5 gallons of fresh fuel.
Fog the engine: Spray fogging oil into the carburetor or through the spark plug holes. This coats the internal parts and prevents rust and corrosion.
Drain the exhaust manifolds and engine block: To do this you will remove the drain plugs to ensure no water remains.
Grease fittings and all moving parts: You want to lubricate all pivot points, steering linkages, and cables because this prevents rust and corrosion as well as extends the life of your bearings and joints.
Disconnect and remove the battery: If you leave the battery in the boat all winter it can lead to corrosion and a dead battery. You should store the battery in a warm, dry place and keep it charged periodically.
For outboard motors-
Flush the engine with fresh water: You can do this by attaching a hose to the flushing port or use ear muffs for a less messy process.
Add fuel stabilizer to your gas tank: You should run the engine for about 10 to 15 minutes so the treated fuel circulates through the system. You should add 1 ounce of stabilizer for every 2.5 gallons of fresh fuel.
Fog the engine: Spray fogging oil into the air intake or directly into each cylinder (check your owner’s manual). This coats the internal parts and prevents rust and corrosion.
Drain any remaining water from your engine: This is an important step to avoid corrosion through winter but it is especially important if you store your boat in any places where temperatures can get below freezing. This is important because if it freezes and cracks your engine, then you're out thousands of dollars. You can drain an outboard motor by storing it all the way down (vertical).
Drain and replace gear oil: Remove the lower unit drain plug and check for any water or metal shavings, if there are you most likely need to speak with a marine technician. If there is not any water or metal shavings you can go ahead and refill with fresh gear oil.
Grease fittings and all moving parts: You want to lubricate all pivot points, steering linkages, and cables because this prevents rust and corrosion as well as extends the life of your bearings and joints.
Bonus: Remove the prop and inspect. This is more maintenance rather than winterization, but you want to check for any fishing lines or debris that has gotten wrapped up around the prop shaft and remove them. You should also grease the shaft before reinstalling the prop.
How to Cover and Store your boat
A big mistake a lot of first time boat owners make is that they use their boat factory or summer cover for winter storage. This is especially bad in areas where there is heavy snow because they are not designed for the weight. This may cause damage to the cover as well as the boat. A winter storage cover should be made of heavy-duty, waterproof material and is often shrink-wrapped for larger boats, you can do this yourself or have it professionally done. Smaller boats may have an option to buy one from the manufacturer or have it custom made. Covering and storing your boat is very important because it prevents water damage, protects from UV and weather, saves you time and money in the spring with repairs and cleaning.
Learning how to winterize your boat is one of the most valuable skills a captain can have. Taking the time to properly clean, protect, and store your vessel ensures that when the weather warms up, your boat is ready for the water, not the repair shop. Winterizing not only saves you money from expensive damages but also helps extend the life of your engine and equipment. By following these steps and using the right products, you can keep your boat in top shape, protect the environment, and start every season on the right foot.
