How to Winterize a Boat

winterized cover boat

Winterizing your boat is an important part of owning and maintaining one of these vessels, which is often quite a large investment. As the temperature turns and water freezes, there are several important steps you must take to protect your boat for the season.

The Importance of Winterizing Your Boat

Since boats are a large investment, it makes sense that they need care, even when they won’t be in use. Water poses a large risk to boats during the winter, as freeze damage can be highly harmful to the engine and structure of a boat. Mildew, rust, and corrosion are other potential problems that your boat could face during the winter due to excess moisture. For that reason, winterizing your boat revolves mainly around removing the threat of water and moisture.

Step 1 - Drain the Engine

Your engine must be drained before the winter to prevent damage during storage for the winter. Warm up the engine while your boat is in the water. Then, drain the engine completely, allowing dirty oil to remove itself and impurities to be flushed away.

adding oil to boat engine

Step 2 - Add New Oil to the Engine

Now, add high-quality oil and filters as needed to the boat engine.

Step 3 - Drain Water from Engine

Your engine isn’t fully winterized yet! Next, drain water from the engine to prevent damage if the water were to be present and freeze. If you have an inboard or sterndrive engine, flush it with clean water by using water muffs, connecting a garden hose to your cooling system. Then flush the engine continuously until it reaches its normal operating temperature.

Complete the process by removing drain plugs, typically found in the engine block and manifold. If necessary, remove the water pump hose to finish removing all water.

If you have an outboard engine, ensure all drain holes are open. Turn the engine on and clean the cooling system by flushing it with fresh water. Flush for several minutes.

Step 4 - Stabilize the Fuel

man fixing boat motor

Neglecting to take care of the fuel in your boat before the winter could result in serious issues with your engine, such as poor performance or even a shorter engine life. Using a fuel stabilizer helps prevent deterioration and thus engine damage during the winter. Add this first and then ensure that your boat is filled with fresh fuel. Then, run the engine for a few moments to let the gas and stabilizer run through the system.

Step 5 - Protect Engine Parts

Because oil drains during the winter when your boat is stored, the inner workings of the engine could end up exposed to the elements. This may result in corrosion and scuffing. To prevent this, protect these parts of your engine with a fogging oil spray. This coats the inner workings of your boat’s engine with a layer of protection, working against corrosion and other engine damage.

Step 6 - Replace Gear Oil

Rid the lower unit of old gear oil and add new oil here once it’s empty. During this step, check for moisture by watching whether water comes out of the lower unit before oil does. If that’s the case, you need to replace the seals.

Step 7 - Add Grease and Lubrication

To ward off rust, corrosion, and oxidation, add grease and lubrication to certain elements of your boat. Use a marine lubricant on the engine’s grease fittings as a precautionary measure.

Step 8 - Clean Your Boat

man cleaning boat

Give your boat a good cleaning, wiping it down, storing cushions, and removing personal items and any valuables for the season.

Step 9 - Cover and Store Your Boat

Now that you’ve taken all of these important measures to protect your boat’s engine, it should be covered completely. Either use a durable cover or shrink wrap to protect it. It’s best to store your boat indoors in a temperature controlled setting that remains dry.

winterized covered boats

As long as you follow these steps carefully, you should be able to rest easy this winter knowing your boat is safe.