Before the temperatures fall below freezing, it’s time to put boats into hibernation. Properly winterizing a boat will help make the spring commissioning a drama-free event and help get you out to enjoy the water safely.

If any of these tasks are more daunting or involve more than you bargained for, don’t hesitate to contact the boat dealer where you purchased your boat or a professional boat repair shop. If you need a recommendation for a company you can trust, reach out to your local Sea Tow captain and see who they would suggest.

Clean Inside and Out

• While your boat is in the water, clean and inspect your trailer. Grease wheel bearings or replace if needed. Inspect and replace tires that exhibit dry rot or excessive tread wear. Replace damaged bunks, lights, wiring, winch components, tie-downs or rollers.
  
  
• Remove everything that’s loose in the boat such as bottles of motor oil, watersports equipment, life jackets, fishing gear, towels and food. Doing this will help prevent mold and mildew from forming. You can find some tips on how to properly store your life jackets over the winter in this blog post.
  
  
• Use a mild, boat-specific soap and warm water with a soft-bristled brush or a cloth to clean the boat inside and out. Ensure everything is dry before closing any hatches.
  
  
• While cleaning, carefully inspect the boat for damage and correct any issues. If the boat was kept in the water, use a pressure washer to clean every surface at or below the waterline, making sure to remove marine growth before it dries and hardens.
  
  
• Fiberglass and painted aluminum boats should receive a coat of wax.

Prepare the Gas Tank and Engine

• For those new to boating, having a dealer perform winterization tasks is recommended since any damage to your boat or motor due to faulty procedures can void the warranty.
  
  
• Most engine problems that happen in the spring are due to old gas with ethanol. So, on the last trip of the year, burn as much gas as possible and then fill the tank with at least ¾ of ethanol-free gas, if you can find it, to avoid phase separation (when water bonds with the ethanol and separates from the gas). Add a fuel stabilizer and run the engine for at least 10 minutes to allow the new gas to clear the old gas out of the fuel lines and engine.
  
  
• When you pull the prop, make sure the seal is intact and that there’s no fishing line wrapped around the shaft. Grease the shaft, reinstall the prop, and use a lock since most thefts occur during winter storage.
  
  
• Change the engine oil and lower unit gear oil. Also be sure to change the oil and fuel filters. If the lower unit is milky white, this is an indication that the shaft seal is compromised and will need to be replaced.
  
  
• Lubricate all grease fittings.
  
  
• Inspect the engine’s hoses and belts and replace them if needed.
  
  
• Read your engine’s service manual and spray an anticorrosive per the instructions – this step will help protect the internal surfaces of your engine.
  
  
• Trim the outboard or sterndrive’s lower unit down to drain it and quickly turn the starter key on and off to clear water from the water pump housing.
  
  
• Remove the batteries and store them in a cool, dry place, periodically using a trickle charger to keep them fully charged.
  
  
• Remove all electronics and store inside, if possible. Spray a silicon sealant on the connector ends and wrap the ends in a plastic bag, especially if the boat is staying outdoors over the winter months.

Use Antifreeze in Freshwater Systems and Toilets

• For simple freshwater systems, pump out the holding tank, drain and add propylene glycol antifreeze. Make sure to read the label before using as antifreeze may require dilution.
  
  
• Run the shower or flush the toilet until you see the antifreeze and don’t use again until spring. Complicated systems should be serviced by professionals.

Cover it and Jack it Up

• To cover the boat, use a tight-fitting tarp that’s well-supported in the middle to withstand the weight of rain and snow, if the boat is being kept outdoors over the winter months. Another option is to have a dealer or professional boat storage facility shrink wrap the boat. This is a good idea whether the boat is being kept indoors or outdoors and is well worth the money it costs.
  
  
• If the boat is on a trailer, jack it up and support the frame with wood blocks to take the weight off the tires. This is also a good theft deterrent.

The Payoff

Properly winterizing your boat means you have less headaches when it comes time to launch it in the spring. Since most of the heavy lifting will be done, you won’t be one of those unlucky boaters in the spring waiting for a hectic repair shop to fit you in to make needed repairs. You’ll just need to take off the cover, complete an inspection, wash the boat inside and out, and bring back all of the equipment and electronics. We’ll be sure to share all the details for spring commissioning in a future blog post. In the meantime, a great activity for the winter months is to take a boating safety class - we have some suggestions for you in this blog post.

If you found this article helpful, please consider a donation to the Sea Tow Foundation today to help us continue our efforts to educate boaters and keep them safe on the water. You can donate securely online at www.boatingsafety.com/donatetoday or by clicking on the DONATE tab at the top of the page.