Winterizing your Sailboat: A Step-by-Step Guide

Winterizing can be complex and involves a lot of tasks, so here is a detailed checklist we use – it’s mainly based on the RYA’s checklist, with some other inputs, such as from West Marine.

The way we look at it, the more we do in the fall, the faster we get in the water in the spring.

In simple terms, you need to either remove anything that could be damaged by freezing and damp or mitigate against that happening. 

	Task	Detail	√
1	Fuel	Fill the fuel tank to prevent condensation and add fuel stabilizer to prevent the growth of diesel bug. Check the fuel-water separator for sediment or water and clean or replace the elements as needed.
2	Engine Oil	Change the engine’s oil and replace the oil filter instead of waiting until spring, so old dirty oil usually contaminated with the acidic by-products of combustion is not left in the engine over winter. Flush the block during the oil change to help remove more of the contaminants.
3	Gear Oil	Check transmission oil and replace if cloudy or milky.
4	Lubricate	Spray some oil into the inlet manifold and crank the engine over a few times (without starting it) to coat the cylinder walls with oil. Grease points on the engine and control cables. Clean then spray unpainted engine areas with WD40
5	Raw water-cooling system	Fill the cooling system with non-toxic antifreeze by removing the raw water intake hose from the seacock and putting it into a bucket with enough antifreeze to fill the engine and plumbing (about two gallons). Start the engine and run at idle until antifreeze comes out of the exhaust. Secure the intake hose back on the seacock.
6	Internal cooling system	Check there is non-toxic antifreeze in the primary cooling system and that it is topped up. If you are not sure, drain the system and replace the fluid with antifreeze
7	Check the Exhaust System	Break the exhaust loose from the water lift muffler or exhaust manifold and inspect for carbon buildup or corrosion. Take the raw water injection hose off the injection nipple and see if it has become blocked by debris or scale.
8	Seal Engine Openings	Remove the air intake filter and block the intake and exhaust with an oily rag to prevent moisture ingress. Block transmission and crankcase breathers. Remember to uncap them in the spring.
9	Batteries	Where possible, remove the batteries. If you’re unable to remove batteries leave them fully topped up and regularly recharged, as full batteries are less likely to freeze in sub-zero temperatures.
10	Inspect Hoses	Check hoses for softness, bulging or cracking. Pay extra attention to the hot side of the exhaust and cooling systems. Check the hose clamps to be sure they are tight and look for corrosion.
11	Engine Mounts	Inspect the motor mounts and check their flexible rubber elements for softening caused by leaks of oil or diesel fuel.
12	Belts and drive wheels	Relax or remove all belts and protect the drive wheels. Rust on these can chew up a belt very quickly in the new season.
13	Potable Water System	Drain water from all freshwater system lines and pumps. Check impellers for wear and lubricate with Teflon®-based grease. Inspect hoses for signs of softening, cracking, bulging, leaks or pinholes and replace, if necessary, before filling lines. Fill all plumbing system lines with nontoxic antifreeze.
14	Interior	Clean and drain bilge completely. Inspect and lubricate all seacocks. Clean out refrigerator, ice box and freezer. Block door open and leave an open box of baking soda inside to absorb odors. Remove cushions and curtains and store ashore. Check and clean all storage compartments. Secure all hatches and ports. Place dehumidifying devices. Check to make sure ventilators are operating properly.
15	Marine Sanitation Systems	Empty waste holding tank at an approved pumpout facility. Rinse holding tank thoroughly to remove residual waste. Pump antifreeze through bowl. Lubricate gaskets and seacocks. Check hoses for calcification and signs of wear. Replace if necessary. Wash out vented loops. Fill discharge and intake hoses with antifreeze. Add antifreeze to holding tank to prevent freezing of residual waste.
16	Airflow	Covers should allow air to circulate as proper through-draught will prevent condensation which leads to dry rot, mold, and corrosion.
17	General	Use tight fitting covers for deck-installed electronics. Check your navigation lights are still serviceable. Touch-up paint, remove rust, clean up grease.
18	Stands	Angle the bow slightly upwards so rainwater runs off covers, decks and cockpit.
19	Make a list	List what you’ve done to winterize your boat so you can reverse any changes in the spring.
20	Visit regularly	Check that all is well, especially before and after any strong winds and heavy rain.

Please feel free to contact us with questions and for advice,

Download a PDF checklist by clicking here:

781-797-0433

info@sailsatori.com