Your boat is a big investment and has the promise of many years of enjoyment. In Michigan, the way to ensure your boat will provide you with outdoor water fun for years to come is to winterize it before storing it in the fall. By that, we mean do a few simple things that will prevent damage to your boat’s engine, cooling system, and hull while sitting over the winter months. The steps are simple, but they will go a long way to ensure your boat lasts through the years and performs at peak efficiency.

Replace the Engine Oil. The first thing you need to do is replace the engine oil. Old oil contains moisture and acids that can cause pits in the engine bearings and other engine parts, eventually causing serious damage. While your boat is still in the water, warm up the engine and drain the dirty oil with its impurities. Then replace it with the high-quality oil recommended by your engine’s manufacturer.

Stabilize the Fuel. When gasoline sits in the tank of a stored boat, it can break down in as little as sixty days and cause varnish and gum to build up in your engine. This will result in hard starting, poor engine performance, and reduced engine life. To prevent this from happening, add a high-quality marine fuel stabilizer to your gas tank, then fill it with fresh gasoline completely. If your tank isn’t full, moisture will condense inside which can cause corrosion in your fuel system and engine. 

Drain the Cooling System. One of the biggest dangers to your boat when storing it for the winter is from water. Water freezes, and when it does, it expands and can wreak havoc with your boat’s engine and cooling system. To prevent that damage, it’s imperative that you drain the water from your engine. After flushing the engine with clean water, remove the drain plugs or make sure the drain holes are open, and remove the water pump hose to drain the water.

Protect the Internal Engine Components. Because engine oil drains away during storage, you need to protect your engine’s internal components with a fogging spray, which is an aerosol petroleum treatment for long-term lubrication and corrosion resistance. It forms a thin coat on metal that, unlike motor oil, remains intact over time and will prevent cylinder scuffing and metal-to-metal contact.

Replace the Gear Oil. Be sure to drain the lower unit of old gear oil and replace it with fresh oil. While doing this, check for any signs of moisture, like water coming out first or oil that’s lumpy or milky in color. If you see this, it means your boat has moisture contamination and will likely need new seals before the next boating season.

Grease and Lubricate Your Engine’s Fittings. Check your owner’s manual so you can find and grease your engine’s fittings with a quality, marine lubricant to guard against rust, corrosion, and oxidation.

Remove All Valuables. Remove anything of value from your boat before you store it. There’s very little traffic in boatyards during winter months, which makes them attractive targets for thieves. So be sure to take anything of value with you, especially electronics like depth finders, fish finders, marine radios, and the like. You should also insure your boat, even when it’s not in the water.

Clean and Wax Your Boat. Once you’ve taken care of the engine and fuel systems and cooling systems, you should thoroughly wash and wax your boat’s decks and hull. Dirt and grime can work its way into your boat’s finish and damage your hull. Waxing your boat before storing helps add another layer of protection during the winter months, as well as helping make it ready for the next boating season.

Cover or Store. Dry storage is the optimum method for storing your boat. Many marinas offer storage in a safe, dry, often heated shed. This the most expensive method of storage, but well worth it. A less expensive storage choice is to shrink wrap your boat. Shrink wrapping offers good protection from the elements, except for the cold. At minimum, you should use a durable cover that you can tighten down and secure against the snow and winter winds.