Off-Season Boat Storage Checklist

Cushions, upholstery and moisture

• Dry both sides of every cushion and the foam fully before storage. Stand cushions on edge so air reaches both faces.
• Once dry, store removable cushions and upholstery somewhere dry and ventilated. Taking them off the boat is best.
• Remove electronics, lines, life jackets, fire extinguishers, flares, fenders and any wet towels or gear.
• Wash the boat and let it dry before it gets covered.
• Clean and dry the bilge. Drain the shower sump and any spot where water pools.
• Prop open interior lockers and cabin doors so air can move. Keep exterior hatches and ports closed and secured.
• After removing wet items and drying the boat, place a moisture absorber in the closed cabin and lockers if you use one.

Optional product: An optional moisture absorber such as the Boat Dehumidifier Container can collect excess moisture in enclosed spaces. It does not replace drying cushions or fixing leaks.

Fuel

• Follow the engine, fuel-system and storage facility's requirements for fuel level. Leave the specified expansion space.
• Add a marine fuel stabilizer, following the directions on the bottle.
• Run for the time specified by the engine and stabilizer instructions, with the required cooling-water supply, so treated fuel reaches the whole system.
• Change fuel filters and any fuel/water separators.
• Gasoline engines onlyUse ethanol-free gas for the storage fill if it is available where you live.

Engine, lower unit and drives

Per your engine manual. Typical items it will cover:

• Raw-water cooled engines: flush the raw-water passages with fresh water, then drain them or run antifreeze through as the manual directs.
• Closed cooling systems: check the coolant mix and condition as the manual directs. The raw-water side still needs its own winterizing.
• Change the oil and oil filter.
• Check and service lower-unit or sterndrive gear lubricant. Investigate water contamination before freezing weather.
• Fog the engine using the method your manual specifies.
• Inspect anodes and replace any that are worn.

Optional product: Outboard Motor Water Muffs, a hose connected flushing muff for compatible outboard and I/O engines.

Water systems

• FreshwaterWinterize freshwater tanks, pumps, hot and cold lines, showers and the water heater.
• FreshwaterUse potable-water-system winterizing antifreeze (propylene glycol) where specified. Never use automotive coolant in drinking-water plumbing; BoatUS notes ethylene glycol coolant is highly toxic.
• SanitationPump out the waste holding tank at an approved facility, then winterize the toilet and sanitation lines. Empty and remove any portable toilet.
• Raw waterGet the water out of raw-water washdowns, livewells and strainers, per the owner's manual.
• Other equipmentCheck applicable generators, air conditioning, strainers and other water-holding equipment against their own manuals.

Optional product: Boat and RV Winterizing Kit, a gravity flow antifreeze tank with hose, valve and fittings.

Batteries

• AshoreIsolate batteries as the manuals direct, or take them home to a cool, dry place above freezing.
• AfloatKeep automatic bilge pumps and required monitoring powered. BoatUS advises wiring the bilge pump directly to the battery (fused) so it runs with the main panel switched off.
• Lead-acidCharge and maintain as specified. A partially charged battery is more likely to freeze. Use a marine charger with a float or maintenance setting, not an automotive trickle charger left on for months.
• LithiumFollow the maker's storage charge level, shutdown procedure and charging-temperature limits. Use a charger approved for that battery.
• Make sure cable connections are tight, clean and free of corrosion.

Cover or shrink wrap

• Make sure the cover has vents. BoatUS Foundation's advice: a boat needs to breathe while it's covered.
• Give it enough support that rain and snow run off instead of pooling. Supports that come with a cover aren't always strong enough.
• Pad corners, sharp edges and both ends of the support poles so the cover doesn't chafe through as it settles.
• AshoreNever tie the cover to jack stands or support blocks; a strong wind can pull the stands out.
• For shrink wrap, Discover Boating recommends a professional job. A tarp that isn't supported and secured well tends to leak, rip or collapse.

Optional product: Boat Cover Support Poles, telescoping aluminum poles that lift a boat cover.

Ashore: hull support and drainage

• Have a qualified yard block and support the hull at manufacturer-approved locations and secure the stands properly. Ask your boat's manufacturer for a blocking plan and keep a copy.
• Keep the boat level so rainwater drains instead of pooling.
• Recheck the stands about two weeks after haul out, once the boat has settled.
• Remove the drain plugs and put them somewhere you will find them in spring.

Optional product: Boat Transom Drain Plug Kit, a replacement transom drain plug and housing in stainless or brass.

Ashore: trailer

• Rinse the trailer brakes with fresh water if the trailer has been in salt water.
• Service bearings on the axle or hub manufacturer's schedule. Dexter, for example, specifies lubrication every 12 months or 12,000 miles.
• Check tire age. Discover Boating, citing the NTSB, says tires over six years old should be replaced.
• Cover the trailer light plug on the tow vehicle so the pins don't corrode.

Optional product: Marine Grease Tube, waterproof marine grease in 3 oz tubes or 14 oz cartridges.

Afloat: in the slip

• Close all seacocks except cockpit drains. BoatUS says a boat with below-waterline thru-hulls that can't be closed should be stored ashore.
• Double clamp thru-hull hoses, especially cockpit drains, with stainless hose clamps where possible.
• Test the bilge pump and float switch, and keep the bilge clear of debris that could clog them.
• Check dock lines and chafe guards, center the boat in the slip and adjust fenders.
• Plug exhaust ports if your checklist calls for it, and write it down so the plugs come out before the engine runs.
• Secure all ports and hatches.

Food, trash and openings

• Clear out every bit of food, crumbs and trash.
• Repair unintended openings with suitable marine materials. Keep designed vents, fuel vents, drains and scuppers clear.
• Close propane valves and take portable canisters home.

During storage

• Visit the boat at least once a month and after heavy rain or snow.
• Clear pooling water off the cover, readjust straps and look for new wear points. Make sure the cover vents are still open.
• Look inside for leaks or standing water, and check that drains and scuppers are clear.
• If you use a moisture absorber, check it and empty or replace it when full.
• Check battery charge the way the battery maker specifies, and recharge if needed.
• AfloatConfirm the bilge pump still works and the boat is not taking on water. BoatUS: if the bilge pump runs, the boat is taking on water.
• AfloatCheck dock lines, chafe gear and fenders after storms.

Spring recommissioning

• AshoreReinstall the drain plugs before launch.
• Remove any exhaust plugs and reopen the seacocks you closed.
• Reconnect the batteries and any systems you isolated, following the manuals.
• Flush winterizing antifreeze from the freshwater system as the manual directs.
• Put life jackets, fire extinguishers, flares and other safety equipment back aboard and check their condition.
• TrailerTires lose a pound or two of pressure a month. Before towing, check cold tire pressure against the trailer manufacturer's specification for the fitted tires and load.
• Put cushions back aboard only once they and the boat are dry.