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Do-It-Yourself: Winterizing Your Boat

Winterize Your Boat
Video Advisor Winterizing Advice & Checklist
Winterizing Your Boat: Introduction to the 5 Step Process Winterizing Your Boat: Introduction to the 5 Step Process
by West Marine 1:47
How to Prepare Your Boat for Winter - Introduction to the 5 Step Process on How to Winterize Your Boat
Winterizing Your Boat: Step 1 Cleaning Your Boat Winterizing Your Boat: Step 1 Cleaning Your Boat
by West Marine 1:29
How to Prepare Your Boat for Winter - Step 1 in the five step process on How to Winterize Your Boat: Cleaning Your Boat
Winterizing Your Boat: Step 2 The Engine & Lower Unit Winterizing Your Boat: Step 2 The Engine and Lower Unit
by West Marine 10:01
How to Prepare Your Boat for Winter - Step 2 in the five step process on How to Winterize Your Boat: The Engine & Lower Unit
WInterizing Your Boat: Step 3 Freshwater & Waste Systems Winterizing Your Boat: Step 3 Freshwater and Waste Systems
by West Marine 1:47
How to Prepare Your Boat for Winter - Step 3 in the five step process on How to Winterize Your Boat: Freshwater & Waste Systems
Winterizing Your Boat: Step 4 Cabin & Interior Winterizing Your Boat: Step 4 Cabin and Interior
by West Marine 2:17
How to Prepare Your Boat for Winter - Step 4 in the five step process on How to Winterize Your Boat: Preparing the Cabin & Interior
WInterizing Your Boat: Step 5 Final Inspection & Proper Covering Winterizing Your Boat: Step 5 Final Inspection and Proper Covering
by West Marine 5:29
How to Prepare Your Boat for Winter - Step 5 in the five step process on How to Winterize Your Boat: The Final Inspection & Proper Covering
Choosing the Right Antifreeze Choosing the Right Antifreeze for Your Boat
by West Marine 1:47
How to Choose a Boat Heater How to Choose a Boat Heater
by West Marine 3:29
Whether you are living aboard, or getting ready for the winter months, West Marine has a variety of heater to suit your needs.
How to Choose a Boat Heater Buyer's Guide to Fuel Additives
by West Marine 4:16
Whether you're getting ready for the winter season or just looking to enhance the performance of your engine, West Marine has a wide selection of fuel additives to keep your engine going.
Engine Flushers Selecting Engine Flushers
by West Marine 1:26
Keep your engine running smooth!

Winterization Advice and Checklist

This winterizing checklist was inspired by Nigel Calder's invaluable Boatowner's Mechanical and Electrical Manual (Model 7103625) and by the suggestions of the folks at Philbrook's Boatyard in Sidney, BC, on Vancouver Island.

Selecting Antifreeze

The chemical in antifreeze that resists freezing is either ethylene glycol (EG) or propylene glycol (PG). Propylene Glycol is odorless, tasteless, biodegradable, and nontoxic. While it is slightly more expensive to produce, it offers a combination of safety and effectiveness we feel makes it a superior choice for marine use. Read full article

Regular Care

For boats that are kept in the water we suggest a care schedule during the winter months that includes regular security and systems checks. If you are away, make a point of having someone drop by and check the condition of shore power connections, mooring lines, fenders and boat canvas / covers. Also, check the condition of shore power lines (feel for warm plugs or hardened points near connectors). Run the engine(s) for an hour every month. Take the time to check fuses and any operating electrical equipment, open the bilges and cycle the bilge pumps to ensure operability.


Each spring, boatyards and suppliers are swamped with yachts and owners looking to have equipment replaced. In most cases, the equipment didn't function as well as it should, or the owners saw new equipment that worked better during the last season or at a boat show. You can avoid the rush by replacing old and malfunctioning equipment with new and properly installed items during the winter months so it can be tested before shoving off for your next cruise.

Engine and Gear Train

Change the engine oil, transmission oil and antifreeze.
Replace fuel filters and oil filters.
Add oil stabilizer.
Drain the raw water system, taking particular care to empty all low spots. Remove rubber pump impellers, lightly grease with petroleum jelly and replace. Leave the pump cover screws loose so that impellers won't stick in the pump housings. Run the engine for a few seconds to drive any remaining water out of the exhaust. Wash salt crystals out of any vented loops.
Replace water with engine antifreeze.
Check the primary fuel filter and fuel tank for water and sediment.
Keep a diesel tank full to cut down on condensation. Run gasoline tanks down to a minimum amount of fuel and add fuel stabilizer. (Note: Modern fuels lose their octane ratings when stored, which can cause engine damage.)
Squirt some oil into the inlet manifold and turn the engine over a few times (without starting) to spread the oil over cylinder walls.
Drain crankcase oil and replace.
Replace lower unit gear lube.
Lubricate all grease points: tilt/trim, steering, control cables, etc.
Remove and inspect spark plugs.
Inspect ignition wires and system components. Replace as necessary.
Use an engine flusher to remove salt, silt and sediment from engine's lower unit.
Remove the inner wires of all engine control cables from their outer sheaths; clean, inspect, grease, and replace. Check the sheathing.
Seal all openings into the engine (e.g., air, inlet, exhaust) and the fuel tank vent. Put a conspicuous notice somewhere so you remember to unseal everything at the start of next season.
Inspect all hoses for signs of softening, cracking and/or bulging.
Clean and degrease engine.
Apply touch-up paint as needed.
Spray corrosion inhibitor on engine exterior.
If hauling out: Check for propeller blade misalignment and cutless bearing wear; tighten any strut mounting bolts; inspect stainless steel prop shafts for crevice corrosion; remove prop nut and check under it.
Store prop indoors.

Stuffing Boxes

If hauling out, repack.
If wintering in the water, tighten down to stop any drip.
Be sure to loosen before reusing the propeller or the shaft will overheat.


Cable Steering:

Remove cables from conduits, then clean, inspect, grease, and replace them.
Also check sheave mountings and clean, inspect and lubricate cable ends.

Rack-and-Pinion Steering:

Remove top plate and input socket screws; clean, grease and replace.

Hydraulic Steering:

Top off fluid and check all seals and hoses for leaks and/or damage.


Bring to a full charge.
Equalize flooded batteries.
Top up.
Clean the battery tops.
Unless the batteries are being properly float charged (via a solar panel or battery charger with float regulation) remove from the boat and store in a cool, dry place.
Bring flooded batteries to a full charge once a month.

Generators and Electric Motors

Clean and spray with moisture dispelling aerosol (e.g. WD-40).
Spray brush springs.
Lubricate fittings where necessary, especially the starter motor pinions.

Electrical Circuits

Clean corrosion off all terminals and connectors, protect with petroleum jelly or a shot of WD-40.
Inspect all outlets, especially the external AC shore power socket.
Check coax connectors for water ingress. Repair as necessary and reseal.


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 an appropriate number of dehumidifying devices or a thermostatically-controlled heater in safe areas away from combustible materials.
Check to make sure ventilators are operating properly.


Drain a little fuel from kerosene and/or alcohol tanks and check for water and contaminants.
Close LPG or CNG gas valves at the cylinder.
Renew filaments on filament-type igniters at least every two years.

Electronics and Electrical Circuits

Remove electronic equipment to a warm, dry place.
Clean corrosion off all electrical terminals and connections and protect with petroleum jelly or a shot of WD-40 or other moisture-dispelling aerosol.
Pay attention to all external outlets, especially the AC shore power socket.

Marine Sanitation Devices

Empty waste holding tank at an approved pumpout facility.
Rinse holding tank thoroughly to remove residual waste.
Drain and/or pump system with 30% to 50% antifreeze.
Lubricate gaskets and seacocks.
Check hoses for calcification and signs of wear. Replace as necessary.
Wash out vented loops.
Fill discharge and intake hoses with antifreeze.
Add antifreeze to holding tank to prevent freezing of residual waste.

Freshwater Systems

Pump out and clean tanks.
Drain system and/or pump through a 30% to 50% propylene glycol antifreeze solution.
Use a water heater bypass, if applicable.

Potable Water System

Drain water from all freshwater system lines and pumps.
Inspect pump impellers for wear and lightly lubricate with Teflon®-based grease.
Inspect hoses for signs of softening, cracking, bulging, leaks or pinholes and replace, if necessary, before filling lines.
Inspect hose clamps and replace if necessary.
Fill all plumbing system lines with nontoxic propylene glycol-based antifreeze.
Before recommissioning your vessel, add water freshener/ purifier tabs to freshwater tank to remove residual odors and condition newly added water.


Drain and/or pump through a 30% to 50% solution of antifreeze.
Inspect all vanes, impellers etc. for wear and check for shaft seal leaks.
Remove flexible impellers, lightly grease (with a Teflon-based grease), and reinstall.
Leave covers loose, tighten when recommissioning.
If wintering in the water, check the bilge pump float switch, wiring, switch and battery charge.


If hauling out, pull and grease all seacock plugs if possible.
Dismantle and grease gate valves.
If wintering in the water, close seacocks (except cockpit drains) and closely inspect cockpit drain hoses and clamps.

Hydraulic Systems

Drain a little fluid and check for water or other contaminants.
Top up as necessary.
Check all hoses and seals for signs of damage or leaks.

Wood, Composite and Alloy Items

Check and caulk windows and hatches.
Repair stanchions, grab- and handrails.

Running Rigging

Wash all blocks.
Disassemble and clean where possible
Hot water and vinegar will remove stubborn salt deposits.
Lubricate and re-assemble.
Wash synthetic lines with mild detergent.

Spars and Standing Rigging

Wooden Spars:

Wash and inspect for signs of rot especially around fasteners and halyard exits.
Seal bare spots even if you plan on varnishing or painting.

Aluminum Spars:

Wash and inspect for signs of corrosion, distorted mast walls (around spreader base), crazing, hairline cracks (around welds and cutouts).
Remove and grease fasteners that shouldn't seize up.
Wax spar before storing.

All Spars:

Withdraw mast tang bolts and check for crevice corrosion.
Remove boots or covers from spreader tips.
Remove and inspect head box sheaves, lubricate and replace.
Remove turnbuckle boots and tape, undo all turnbuckles, clean, inspect and lubricate.
Inspect clevis pins.
Tape over the split ends of cotter pins.
Inspect swages for hairline cracks.
Wash all rigging.
Do not store stainless steel wires against aluminum spars.

Winches, Windlasses and Deck Hardware

Strip down, clean and lubricate all winches.
Closely inspect pawls and pawl springs.
Check windlass lubricant for water contamination and replace if necessary.
Crank windlass over to spread lubricant around.
Remove rope drum and gypsy to lubricate clutches and shafts.
Check fasteners on all deck hardware.
Inspect the caulking for damage which may result in leaks.

Roller Reefing Gear

Flush all open bearings with warm fresh water.
Relubricate as instructed by the manufacturer and turn bearings to spread lube around.
Wash extrusions and apply wax.
Pay attention to the joints.
Don't leave the sail on, store it indoors for the winter.

Sacrificial Anodes

Inspect and replace all zincs as necessary (hull, rudder, engine shaft, engine cooling system, refrigeration condenser, etc.)


Check the lay-up list and complete what hadn't been done.
Observe and obey all conspicuous reminder notes and envision places where they should be but maybe aren't (plugged-off engine air inlets, exhausts, overtightened packing nut in the stuffing box, empty hot water tank etc.)
Check hoses and thru-hull connectors.
Undo the hose clamps a turn or two to check for corrosion of the band inside the screw housing.
Check refrigerant on refrigeration systems. Engine-driven compressors may have dried out and become leaky during a long period of being shut down.
Exercise the switches by turning them off and on a few times. This helps clean off the surface corrosion on terminals.
Open and close seacocks.
Spin blocks and windlasses.
Turn the steering wheel from side to side to check for stiff spots or binding.
Spin the drum and halyard swivels on roller reefing systems.
Tighten down all flexible impeller pump housings.
Prime centrifugal pumps.
Once in the water allow wooden hulls to settle for a few days, then check engine alignment.