How Much Does it Cost to De-winterize a Boat?

Last Updated on October 1, 2022

During the duration of winter, you must have wondered – “how much does it cost to de-winterize a boat?” – especially if you’re a boat owner for the first time. De-winterizing a boat involves a series of processes, some of which you can do yourself (if you have the experience) and others that are better handled by professionals.

De-winterizing your boat becomes necessary after you have protected your boat’s engine, components, and ballast system from freezing over in subzero temperatures as is common in winter, to prevent expansion that may lead to damage of components or mold formation in the ballast system. In essence, de-winterization happens after you have done winterization for your boat.

You will get to know how much it costs to de-winterize a boat but before then, you will better understand winterization and de-winterization. You will also understand why it is important that you de-winterize your boat and have professionals handle the process.

What is Boat De-Winterization?

Boat de-winterization is the removal of the antifreeze liquid from all the components and engine parts of your boat. It involves the checks that guarantee that your best is ready for new adventures in the spring, after the cold and freezing temperatures of the winter.

De-winterizing occurs after you have protected your boat from freezing during the winter, by winterizing it. In winterizing your boat, water present in all the components – including engines, heaters, and ballast pumps – of your boat is drained. Anti-freeze liquid is introduced into each system in your boat to protect them from freezing during winter. Also, all ballast bags are removed and stored away in a dry place. Although it’s optional, your boat engine may have an oil change to carry it through the months of doing nothing.

When spring comes, you may decide to get your boat on the water again. If you do so without having the antifreeze you have introduced during winterization, and you run the engine, you have de-winterized your boat, albeit not professionally. However, to ensure that all engine components and other boat parts, such as the engine impeller, are working as they should, you should have your boat de-winterization done by pros.

Processes of De-winterizing a boat

The process of de-winterizing your boat can start from the exterior and end in most interior parts of the boat. However, you can choose to go the other way round. The purpose of de-winterization is to ensure all boat parts and components are in the states they should be for seamless operation.

In no particular order, here are the processes.

Inspect the exterior

As is expected, you must have completed your boat’s winterization by covering it with a tarp, probably. You should begin de-winterization by removing that covering and checking the exterior of your boat out. Look out for cracks or dents that may lead to leaks. If there is any, get it fixed.

Check the trailer

Transporting your boat with ease depends on the health of your trailer. Check the tires for adequate pressure, ensure the wires are properly connected to other attachments, and make sure all lights are functional.

Check hoses and cables

There is a possibility that the cold temperatures have caused dryness that may lead to cracks and break in the hoses and cables of your boat. You are in for a bad day if these problems manifest while you’re out on the water. Therefore, check your hoses and cables for breaks, disconnects, and possible leaks.

Test the steering

See how stiff your boat steering is by turning it both ways. If it feels stiff, there is a high chance the steering fluid level is low and needs to be filled. Ensure to use the right steering fluid for your boat steering system.

Inspect the battery

Batteries are adversely affected by cold weather conditions. They are also not good with sitting unused, as they have to, during the winter months. You will need to clean your battery’s terminal points of any corrosion that may be present. Also, fill the battery with water and connect it to a battery tester, to check if there is any charge.

If there is, you can continue using that battery, but if not, you will need a new battery.

Perform an engine and propeller check

Your propeller is best checked when it’s not working. Check for corrosion that may have occurred during the winter. Also, check for any loose parts and tighten them. If any part is dented and needs to be replaced, do so.

Check the condition of the bolts that connect the engine to the propeller. If they’re dry and have cracks, or are loose, they should be changed. Run the engine and check for any issues.

Check the water pumps and thermostats

The water pumps are essential in keeping your engine cool while the thermostat tells you how hot or the engine gets. It is recommended that you replace the rubber part of the impeller after every 200 hours of operations. You may need to replace it before heading out to water again for better engine cooling.

Also, ensure that the thermostat is functioning. If it isn’t, you should replace it.

Refill the cooling systems

During winterization, your boat cooling system is drained; now, you need to refill it. Mix equal parts of water and antifreeze and supply them to the cooling systems.

Don’t forget the fuel system and distributor

Before you fill your fuel tank with new fuel, check that all the fuel lines and hoses have no cracks that may leak. If you notice any cracks, it is advisable that you replace the hoses and lines. Also, check the fuel filter to see if it is in a good condition; if not, replace it.

Remove the distributor’s cap to check for corrosion. Also, remove the plastic bag covering the carburetor, and tighten the spark plugs.

What is the Cost to De-winterize a Boat?

While it is possible to de-winterize your boat by yourself; considering all the checks and fixes that may be necessary, it is advisable that a professional handle it. Generally, the cost to de-winterize a boat depends on the size of the vessel and the extent of damage the winter has on it.

A small boat with a single outboard motor may cost about $100 to de-winterize. However, larger vessels, such as a cabin cruiser, can have their de-winterization cost running up to $600. On average, the cost to de-winterize a boat is $300.


De-winterizing your boat may seem like a simple thing to do and yes, you can do it yourself. However, it is better to have a professional handle it, unless you have extensive experience with boats. The cost to de-winterize a boat largely depends on the size of the vessel.