How to Winterize Your Boat?

Last Updated on March 9, 2021

If you are someone who owns a boat and lives in a place where the temperature reaches below zero degrees, you need to take winterization of the boat very seriously.

You might be thinking that avoiding this step will save you money. Well, you are wrong. If you avoid winterization of the boat, you will probably have to spend more amount of money when winter comes.

That’s why in this article I’m going to teach you how to winterize your boat.

Why Is Winterization Required?

It is important because if you miss this process, you will end up having different types of problems in your engine like a crack in any of the parts inside where water flows.

You also might see problems in the electric stuff in your boat. And the worst-case scenario is that there might appear some crack and your boat might get sunk if you do not take enough preparation.


How To Winterize A Boat: 8 Easy Steps

Several steps are required to complete the winterization of your boat. These are the following:

Step 1: Check for Problems in the Fall Season 

You need to solve any running problems in your boat before the winter comes. This means you should check for any minor or major problems in the fall season.

As the winter passes, the boat mechanics will have tons of work in their hands, which makes it late for you to roll in the next spring. By thoroughly checking the boat by any professionals, you are finishing your responsibility as a boat owner.

Step 2: Decide Where You are Going to Keep Your Boat

You have two options regarding this:

Keep the Boat in the Marine Dock

If you want to keep your boat in any marine dock, then you need to understand there are some challenges that come with it. You need to prevent any formation of ice in your boat, winterize your freshwater system and tank, etc.


On top of that, a possibility remains that you may find some crack on the bottom of your boat due to extremely cold temperatures. The best thing about keeping your boat in the water is that as soon as the winter arrives, you can immediately go fishing or cruising.

Keep the Boat out of Water

The very first irritating job in this process is that you need to carry your boat into the storehouse, and it is a tough job to do. When winter is going to fade, and spring starts to appear, then you again need to carry your boat all the way to the marine dock.


And the best part of keeping your boat out of water is that you can be assured that your boat is very well protected from storms or freezing. The level of vulnerability of your boat literally goes lower, which is a big relief if you own a luxurious boat.

Step 3: Buy a Good Cover for Your Boat

Whether you keep the boat in a marine dock or not you must have to buy a cover for your boat which will protect it from the snow and ice. This investment will make sure that you are saving more money by spending a little amount of money.

The best covers are fit covers, but it would be best if you make a custom boat cover. You can also buy a frame and keep it under the cover, which will create a high distance between the snow and your boat.

Step 4: Winter Freshwater System

The very first thing you need to do is to open all the outlet and let the water drain fully. Then you pour the antifreeze into the system and open the outlet again to drain it.

A very little amount of water in the system can freeze, and the result might be disastrous. But by running the antifreeze into the system, you can make sure that there will be no crack in the pipes and valves.

Step 5: Change the Oil and Oil Filter

You should change your oil and oil filter as a part of winterizing your boat.  It is very important because oil can change and become more acidic. Not only that the contaminants of the oil can sit into the engine due to a long period of time.

If that happens, you need to spend a lot of money on your engine. Before changing the oil run your engine for a few moments, and you should also check if there is any leakage of oil.

We have also reviewed some good oil extractor for boat, read this review if you need to buy one.

Step 6: Stabilize the Fuel 

This step can not be neglected at all if you want a good starting in the next spring. You should stabilize the fuel by using a stabilizer. The manufacturer company has a suggestion which stabilizer you can use for your boar.

Load your tank with fuel more than 90% and then run for a few days before the winter. By that time, the stabilizer will have circulated through the system, and due to the amount of fuel, there will be little to no space for the moisture to get absorbed.

Step 7: Remove the Electronic Stuff

Not every electronic equipment is removable from the boat. But you can remove some of them and make sure they are being protected from the cold and moisture. Due to moisture, corrosion of electronics might happen, and few fuses might also take place.

If that happens, that’s going to cost you a handsome amount of money. You should spray any lubricant which will not allow the moisture of the winter to harm the electronic stuff.

Step 8: Winterize the Engine 

It doesn’t matter which model of engine you have. You must drain water from your engine and add the antifreeze. The steps are a bit different for different engines, and these are the following:

For Outboard Boat

The first thing to do is to change the lower unit oil. If there remains a little bit of water in the gear lube, then it can create a huge problem for you.

Then you need to flush the cooling system with freshwater, and it will go downwards as the outward engine is designed to tilt down. After that, there will be no presence of water.

As the winter season will be there for months, you need to fog the engine with the fogging oil. You should apply anti-water grease to the propeller shafts and thread so that it stays safe. Lastly, polish the exterior of the engine, and after that wash with any liquid soap and then rinse it properly.

For Inboard Boat

First of all, you should utilize the water pump and intake pipe. Pour antifreeze into a large bucket. Then stick one opening of the intake pipe into the bucket. Now start the engine and run it until you are seeing that the antifreeze is flowing out from the exhaust pipe.

Then you are fully sure that antifreeze has gone throughout the system. Changing the engine oil and filter is very important. Now remove the spark plugs. After that, you need to have a look at your cylinder.

Take some fogging oil. Then prepare it so that you can spray it into every cylinder. This will stop rust in the heavy winter season.

For Stern Drive

First of all, you need to have a look at the lower part. Try to remove barnacles if you find any. You should change the gear lube in the stern drive.

Then wash it with normal water. Recheck if there is any crack visible. Lastly, you need to check your hydraulic steering. Inside it, you have to check whether the fluid is enough to run it properly.


By this time, you already understand the importance of winterizing your boat. Any boat owner who is caring towards his boat and does not like to waste money would be very careful about this process of winterization.

One thing you should keep in mind is that, if you do not know the process or it seems a bit tough for you, then you should bring a professional to do the job for you. But again if you think that you have the learning capability and will power to do it then just go for it.