Winterizing Your Boat

If you don’t boat year-round, you need to protect your boat in the winter. Lengthen your boat’s life and maintain its high-performance functioning. Insurance policies don’t cover damage from neglect or lack of maintenance.

A great place to start is to get a checklist together. Make a shopping list of everything you’ll need to buy. Review your owner’s manual for specific winterization requirements for your model. 

If this is your first time winterizing, you might want to ask a more experienced friend. Here are some fundamentals to hit, no matter what kind of boat you have.

Engines

• Change the oil (run the engine first to warm the oil before you drain it)
• Flush the engine with non-toxic antifreeze 
• Change transmission fluid
• Take off spark plugs, spray “fogging oil”  into each cylinder 
• Clean the engine with a shop towel sprayed with a little fogging oil 

Stern Drive

• Inspect the stern drive, remove plants or barnacles from the lower unit
• Drain the gear case and check for moisture in the oil (this could mean there is a leak in the seals)
• Clean the lower unit with soap and water.
• Check rubber boot on the sterndrive for cracks or pinholes. (located between the transom & engine) 
• Grease fittings
• Check the fluid in hydraulic steering or lift pumps
• Check your owner’s manual for extra suggestions and requirements 

Outboard Engine

• Treat the remaining fuel in the tank with an adjusted amount of a fuel stabilizer
• Flush engine with fresh water with flush muffs or using the flushing port
• Spray fogging solution into the air intakes located on the front of the engine (be sure you’ve started the engine and left it running)
• Remove the fuel line from the engine and spray the fogging solution until the engine shuts down (running the engine with the fuel line removed burns fuel from the carburetors to prevent build-up)
• Put water-resistant grease onto the propeller shaft and threads
• Change the gear oil in the lower unit
• Lubricate the outside of the engine or polish with wax
• Wash the engine with soap and water and rinse any residue left

Fuel

• It is a good idea to fill your fuel tanks and add a stabilizer to the fuel (this leaves less room for condensation to form)
• Ethanol may spoil over the winter, so add a fuel stabilizer
• Change fuel filters and water separators

Bilges

• Soap, hot water, and a stiff brush is great to clean up oil
• After the bilges are clean, spray with a moisture-displacing lubricant
• Add antifreeze to prevent water from freezing

Freshwater System

• Completely drain the freshwater tank and water heater
• Pump a non-toxic antifreeze into the system 
• Put non-toxic antifreeze into the water heater

Head

• Pump out the holding tank at an approved locations
• During pumping, add fresh water to the bowl and flush several times.
• Use Vanish crystals or whatever will not harm your system and let sit for a few minutes.
• Add fresh water and pump out again
• Add antifreeze and pump through hoses, holding tank, y-valve, macerator and discharge hose
• Be sure to check your owner’s manual, in case alcohol-based antifreeze damages your system.

Interior

• Remove valuables, electronics, PFD, fire extinguishers, lines, flares, fenders, and so forth
• Cleaned, checked and replaced items over the winter as necessary
• Clean drawers and lockers
• Turn cushions up to air them out, or even better, take them and store them at home
• Clean the refrigerator and freezer
• Get a dehumidifier or some odor/moisture absorber products

Out of Water Storage

• Pressure wash the hull, clean barnacles from rudders, props and shafts,  trim tabs and struts
• Clean all thru-hulls and strainers
• Open seacocks and allow water drainage
• Check the hull for blisters and let your service manager know
• Wax the hull 
• Charge or remove dead batteries, turn off switches

In-Water Storage

• Close all seacocks 
• Check rudder shafts and stuffing boxes for leaks, repack or tighten as needed
• Keep battery charged, clean terminals, add water when needed, and double-check the charging system is working
• Make sure bilge pumps are working and float switches activate the pumps, make sure they are not blocked by debris
• Check your boat often to avoid leaks, animal inhabitants, and to detect theft early

Always keep your boat under a cover and out of the water when possible. 

If you don’t want the monthly fee of renting a space at boat storage, a lower-cost alternative to is shrink-wrapping the boat and using a boat cover. Many dealerships offer shrink wrapping, call your local dealer to find out.  Short of these two items, make sure that your boat is well covered with a tarp or some other sturdy cover.

Please make sure you review your boat’s manual. We’ve provide you with some great basics, but there will be requirements for your specific boat. Try not to do your first  winterizing job without help from an experienced friend or professional. Your local marina may have suggestions. Good luck, you’re on the right path to keeping your boat in tip-top shape for many years to come.