End-of-season and winter lay-up checklist

End-of-season lay-up comes down to five jobs: winterise the engine, protect the deck and gear, unbend and dry the sails, ventilate and de-humidify the interior, and inspect the hull, safety equipment and systems. The whole point is to put the boat to rest shielded from the three enemies of a winter afloat or ashore — damp, mould and frost — so that when spring arrives you find her in the same order you left her, rather than facing a long list of repairs and a musty cabin. A proper lay-up is not a single afternoon of work but a sequence of small, deliberate tasks, each of which prevents a specific kind of damage. Frost cracks engine blocks and splits water lines; salt left in a winch turns to a grinding paste; a damp sail bag becomes a mould nursery; still air below deck breeds the smell that takes months to shift. Work through the checklist that follows area by area, and you will have covered every part of the boat that suffers over the cold months.

Engine and systems

The engine is the single most delicate part of any lay-up, and the part where a mistake is most expensive, so it deserves your attention first while you still have daylight and patience. In regions where winter brings a hard frost, the risk is not gradual wear but sudden, catastrophic failure: water left in the cooling circuit or the raw-water system expands as it freezes and can crack the block, the heat exchanger or the exhaust elbow overnight. Even in milder climates, a season of combustion by-products and moisture sitting in the crankcase and the fuel tank will quietly corrode internal surfaces if you leave them untouched for four or five months. The core of engine lay-up is therefore threefold: change the oil and filters so the internals sit in clean lubricant rather than acidic old oil, protect the cooling circuit against freezing, and treat the fuel so it does not degrade or grow diesel bug. For the full step-by-step routine, including how to run antifreeze through the raw-water side, follow the dedicated guide on how to winterize a sailing boat motor.

Oil, filters and fuel

Change the engine oil and the oil filter with the engine warm, so the old oil carries out as much suspended contamination as possible before it goes to rest for the winter. Used oil is mildly acidic and holds combustion residues in suspension, and if you leave it in the sump those acids sit against bearings and cylinder walls for months, which is exactly the slow corrosion you are trying to avoid. Once the fresh oil is in, turn to the fuel system: fill the tank close to full to minimise the air space where condensation forms, then add a diesel stabiliser and, if your climate or usage warrants it, a biocide to keep diesel bug at bay. Check and, if due, replace the primary and secondary fuel filters, and drain any water from the separator bowl so you start the season with a clean supply. A tank that is nearly full and treated will not develop the water layer and microbial growth that clogs filters and stalls engines on the first outing of spring.

Cooling circuit and antifreeze

The cooling circuit is where frost does its worst damage, so treat it with real care rather than a token gesture. On the freshwater side of an indirect-cooled engine, check the concentration of the coolant with a tester and top up or renew it so the mixture protects to a temperature comfortably below the coldest you expect. The raw-water side is the vulnerable one: close the seacock, remove the impeller inlet hose, and draw non-toxic antifreeze through the system by running the engine briefly until the coloured fluid flows from the exhaust, which confirms it has reached the whole circuit. It is good practice to remove the raw-water impeller entirely for the winter so its vanes do not take a permanent set against the pump housing, storing it in a labelled bag ready to refit in spring. Leave a clear note at the helm or on the ignition reminding you that the impeller is out and the seacock closed, because starting a dry engine in the spring will destroy a new impeller in seconds.

Batteries and electrical systems

Batteries lose charge over a long lay-up, and a battery left flat through a cold winter can freeze and be ruined, so they need a deliberate plan rather than neglect. The simplest approach is to fully charge each battery, disconnect it and store it in a dry, frost-free place, checking the state of charge every few weeks and topping up as needed. If the boat has shore power and a good multi-stage charger, you can instead leave the batteries in place on a maintenance or float charge, which keeps them healthy without overcharging. Either way, turn off all non-essential circuits, disconnect the negative terminal to eliminate parasitic drains, and clean and lightly grease the terminals to keep corrosion at bay. Take a moment to look over the wider electrical system too: check for chafed wiring, corroded connections and any bilge pump that will need to keep working while the boat sits, because a stuck float switch and a slow leak is a combination that sinks boats on their moorings over winter.

The hull and below the waterline

If the boat is coming ashore for the winter, the lift-out is your best and cheapest chance of the year to inspect everything below the waterline, so plan to spend time under her the day she comes out. As soon as the hull is pressure-washed and still damp, walk around it and look closely before the growth dries on and becomes hard to read: fresh out of the water you can spot blisters, damaged antifouling, worn anodes and weeping fittings far more easily than you can after weeks in the yard. This inspection is not a lay-up job in isolation but part of the routine care every boat needs, and it dovetails with the broader programme covered in the guide on sailboat maintenance. Note anything that needs attention on a list so that the quiet winter months become useful working time rather than a scramble in the spring when the yard is busy and every contractor is booked.

Anodes and seacocks

Sacrificial anodes are cheap insurance for expensive metal, and the lay-up is the natural moment to assess them and plan replacements. Check each anode — on the shaft, the hull and any that protect the rudder or trim tabs — and replace any that are more than about half wasted, because an anode that disappears mid-season leaves your propeller, shaft and skin fittings exposed to galvanic corrosion. While you are working around the fittings, exercise every seacock: open and close each one to make sure it moves freely, and if any is stiff, seized or weeping, mark it for service or replacement while the boat is out of the water and the job is easy. Leave seacocks in the position that suits your lay-up plan — generally closed for a boat ashore, and carefully considered for a boat afloat — and keep a mental or written map of which are open, because an overlooked open seacock with a failed hose is a classic cause of a sunken boat.

Antifouling, gelcoat and osmosis

With the hull washed and dry, assess the antifouling and the gelcoat so you know what the spring will demand. Light touch-ups may be all that is needed, but if the coating is failing over large areas the winter is the time to plan a proper strip and re-coat rather than slapping fresh paint over a poor base. Look for gelcoat blisters below the waterline, which can signal osmosis; a few small ones are common and manageable, but widespread blistering warrants opening, drying and filling over the winter when the hull has months to dry out properly. Check the leading edges of the keel and rudder for impact damage, and inspect the keel-to-hull joint for any cracking or weeping that suggests movement. Catching these issues at lift-out, rather than at launch, turns them from an emergency into a straightforward off-season project.

Rig and deck

The deck must be cleared of everything that traps moisture or degrades in sunlight, because ropes, canvas and fittings left exposed all winter come back stiff, faded and salt-laden. Running rigging, wherever it is practical, should be unrove, washed in fresh water and stored dry indoors; where lines must stay in place, coil them off the deck and protect them so they are not sitting in standing water. Winches, clutches and blocks should be washed free of salt and covered, because salt is hygroscopic and will draw moisture into every mechanism it contaminates. Take the chance to look over the standing rigging as well, since a boat de-rigged or at rest is far easier to inspect than one you are trying to sail. The table below summarises the main deck areas and the action each one needs.

Area	Action
Running rigging	Rinse in fresh water, dry thoroughly, store indoors or protect in place
Winches	Wash off salt, service and grease, then cover
Clutches and blocks	Rinse, free off sticking cams and sheaves, lubricate lightly
Guardrails and grab rails	Rinse and protect exposed runs and fittings
Deck and teak	Wash, dry and cover where possible
Standing rigging	Inspect terminals, spreaders and swages for corrosion or cracks

Covered winches stay smooth and dry all winter, which is exactly what you want when the boat sits idle for months at a time. An anti-mould cover keeps salt, rain and condensation from working their way into the mechanism during lay-up, so the gears you serviced in the autumn are still turning sweetly when you pull the covers in spring. It is a small, reusable piece of protection that saves you re-doing the strip-down every single season.

Running rigging

Running rigging spends the sailing season absorbing salt, sun and grit, and if you store it in that state the fibres stiffen and the covers abrade from the inside. Where you can, take the halyards, sheets and control lines off the boat entirely: run a messenger line through each halyard sheave first so you can pull the working line back through in spring without climbing the mast. Wash the lines in fresh water — a soak in a tub or a gentle machine wash in a pillowcase both work — then hang them to dry completely before coiling them loosely and storing them somewhere dry and dark. Lines that must stay aboard should be led away from standing water, and any that pass through clutches should be eased so the cams are not clamped under tension for months. This is also a good moment to note lines that are chafed, glazed or losing their cover, so you can budget for replacements before the season starts.

Winches, clutches and blocks

Winches carry the heaviest loads on deck and rely on clean, greased internals to work smoothly, so servicing them before the boat rests is one of the highest-value jobs on the whole checklist. The reason is simple: salt left inside a winch over the winter draws in moisture, turns the old grease into a gritty paste and is the single most common cause of stiff, notchy gears when you come to use them in spring. Strip each winch down, wash the parts in a suitable solvent, inspect the pawls and springs for wear, then re-grease the gears and lightly oil the pawls before reassembly — the full procedure is laid out in the guide on how to service a winch. Once they are clean and greased, cover them so that the work you have just done is not undone by a winter of condensation and salt spray. Give the clutches and blocks the same courtesy: rinse them, free off any sticking cams or sheaves, and add a touch of lubricant so nothing seizes over the cold months.

Guardrails, deck and teak

The deck itself needs a thorough fresh-water wash to lift the season's salt, which otherwise holds moisture against every surface it coats and encourages mould in the non-skid texture. Pay attention to the low corners and channels where dirt and water collect, and clear any scuppers and drains so that winter rain runs off rather than pooling on deck. Rinse the guardrails and grab rails and protect the exposed runs, particularly where wire or webbing passes through stanchions and can trap grit. If the boat has teak, wash it gently along the grain, let it dry, and cover it where you can, because months of UV and standing water are what grey and split a deck fastest. Finally, if you are using a full winter cover or tarp, build in ventilation and slope so that water and any snow load run off cleanly rather than sagging into pools that eventually find their way below.

Sails

Sails should come off the boat for the winter, because a sail left bent on and exposed to months of UV, flogging and damp is a sail you are ageing prematurely for no reason. Unbend the mainsail and headsails, and if they carry the salt, grime and stains of a full season, wash them appropriately before they go into storage. Above all they must be bone dry before they are folded or bagged and put away, because storing a sail damp is the single surest way to find it spotted with mould and smelling stale when you unroll it in spring. Once dry, store them loosely in a well-ventilated space out of direct sunlight, ideally flaked rather than crammed hard into a bag where permanent creases can set into the cloth.

Washing and drying

Washing sails is a job to do gently and patiently, since aggressive scrubbing or harsh chemicals can damage the cloth, the coatings and the stitching. Lay the sail out flat on a clean surface, sponge it down with fresh water and a mild soap, pay particular attention to salt-crusted areas and any mildew spots, and rinse thoroughly so no detergent residue remains. The detailed method, including which products are safe and how to tackle stubborn stains, is set out in the guide on how to clean sails. Drying is where most mistakes happen: the sail must be completely dry through every layer, including the reinforced corners, the batten pockets and the luff tape, before it is folded away. Give it time in a dry, airy space, turning it if necessary, and resist the temptation to bag it while any part still feels cool or damp to the touch.

Storage and inspection

With the sails clean and dry, the lay-up is the ideal time to inspect them properly and note any repairs for the sailmaker to handle over the quiet winter months. Run your eye and hand over the seams, looking for stitching that is chafed, sun-rotted or starting to lift, and check the high-load points — head, tack, clew, reef points and batten pockets — where wear concentrates. Look for small tears, UV degradation along the leech and foot, and any hardware that is loose or corroded. Sending sails to the loft in the autumn means they come back fresh and ready before the spring rush, rather than sitting in a queue when you want to be sailing. Store them somewhere with stable temperature and good airflow, and keep them clear of oil, fuel and anything sharp that could nick the cloth.

Interior

Below deck, the enemy is still, damp air, and the whole interior strategy is built around removing moisture and keeping what remains moving. Empty the lockers, clear out the fridge and any food, and leave hatches, cupboard doors, drawers and locker lids open so that air can circulate freely through every enclosed space rather than stagnating in sealed compartments. Lift berth cushions on edge or stand them on their ends so air reaches both faces, and place moisture absorbers or a low-power dehumidifier in the cabin to soak up the damp that inevitably builds over winter. A boat closed up tight and left alone is a boat that comes back smelling of mould, whereas one that can breathe stays fresh with very little effort. The same twofold principle governs everything here: take the water out, and keep the air moving.

Ventilation and moisture control

Mould and the stale smell that goes with it almost always trace back to a combination of trapped moisture and dead air, so break both and you break the problem. Ventilation does not mean leaving the boat wide open to rain and vermin; it means arranging steady, low-level airflow through the cabin using dorade vents, cracked hatches under a cover, or a small solar or mains-powered fan that keeps the air turning over. Pair that airflow with active moisture removal — rechargeable desiccant tubs, hanging absorber bags or a thermostatically controlled dehumidifier if you have shore power — and empty or recharge them on your winter checks. Wipe down and dry any surface that shows condensation, particularly the hull sides behind lockers and under berths where cold meets warm. A cover that breathes will always beat a sealed tarp that traps condensation underneath and effectively rains on the boat from the inside.

Galley, heads and tanks

The plumbing and tanks need their own attention, especially where frost can freeze standing water in pipes, pumps and the heads. Drain the fresh-water tank and run the taps until the lines and the water heater are empty, or where freezing is a real risk, run non-toxic antifreeze through the system so any water that remains cannot expand and split a pipe or a pump body. Pump out and flush the holding tank, then treat the heads by drawing antifreeze through the bowl and pump so the valves and seals do not freeze or dry out and crack. Empty the fridge, prop its door open and clean it so it does not grow mould in the dark, and give the galley a wipe-down to remove crumbs and grease that attract pests. Leave nothing edible aboard, since even sealed dry goods will draw rodents and insects into a quiet boat over a long winter.

Safety gear

Safety equipment is easy to overlook during lay-up because it is not part of putting the boat to rest, yet the off-season is the ideal window to service it while the boat is stationary and you have time to be thorough. Much of this gear carries expiry dates or requires periodic professional servicing, and discovering an out-of-date flare or an overdue liferaft the week before your first spring passage is exactly the scramble a good lay-up avoids. Gather everything in one place, check the dates, and build a list of what needs renewing or servicing so it can be booked into the quiet months rather than the busy pre-season. Store anything that suffers from cold, damp or UV somewhere dry and stable, and note where each item lives so it goes back in the right place come spring.

Lifejackets, harnesses and the liferaft

Take the lifejackets home, rinse them in fresh water and let them dry completely, then inspect each one before storage. Check that the automatic inflation cartridges and firing heads are in date and not corroded, look over the bladder for chafe or damage, and open any that are due for their manual inflation test to confirm they hold air overnight. Rinse and dry the harnesses and tethers, and check the stitching and clips for wear, replacing any tether whose webbing is faded or frayed. If the boat carries a liferaft, check its service date and book its periodic inspection at an approved station over the winter, since this is specialist work and the stations are far less busy off-season. Store lifejackets loosely and dry rather than compressed, so the fabric and the firing mechanisms are ready to perform when you need them.

Extinguishers, alarms and bilge pumps

Fire extinguishers should be checked for pressure on their gauges, weighed if required, and replaced or serviced if they are out of date or discharged, because a lay-up boat with a battery on charge is not free of fire risk. Test the gas alarm and the carbon monoxide and smoke detectors, and renew any batteries so they keep watch through the winter if the boat is left connected to shore power. Turn off the gas at the bottle and consider removing the cylinder to a safe, ventilated store ashore. Finally, do not neglect the bilge pumps: clean the strainers, test that both manual and electric pumps move water, and confirm the float switches operate freely, because a slow leak and a working automatic pump are all that stand between a boat afloat and a sinking over a long, unwatched winter.

In the water or ashore

Whether you lay the boat up afloat or ashore shapes several of the jobs above, and the right choice depends on your climate, your berth and how much winter attention you can give her. A boat hauled out ashore is protected from ice damage to the hull, is far easier to inspect and antifoul, and lets you work on seacocks and the keel joint at leisure, at the cost of yard fees and the need to support and cover her well. A boat left afloat avoids the lift-out cost and stays in her element, but she demands more frequent visits to check the mooring lines, chafe gear, seacocks and bilge, and she is exposed to ice in colder harbours. Whichever you choose, the underlying checklist barely changes — engine, deck, sails, interior and safety gear all need the same care — but the hull and seacock work leans heavily on having the boat out, and the mooring and bilge watch leans on her being in. Decide early, because the choice affects when you book the yard and how you plan the whole autumn.

Frequently asked questions

When should I start the lay-up?

Start as soon as the sailing season ends and, crucially, before the first hard frost arrives in your area. The engine and plumbing jobs are the time-sensitive ones: water left in a cooling circuit or a water line can freeze and crack expensive components in a single cold night, so those tasks should be done while there is still no risk of frost. The deck, sail and interior work is less urgent but benefits from being done in mild, dry autumn weather when you can wash and dry everything properly rather than fighting the damp. Acting in good time turns lay-up into a series of unhurried afternoons instead of a panic ahead of a cold snap.

Do I need to unbend the sails?

Yes, whenever it is practical to do so. Sails left bent on over the winter suffer needlessly from UV, flogging in winter gales and trapped damp, all of which shorten their working life. Taking them off, washing them if they need it, drying them thoroughly and storing them out of sunlight in a ventilated space is one of the best returns on effort in the whole lay-up, and it gives you the chance to inspect the seams and high-load points and book any repairs with the sailmaker over the quiet season. If you genuinely cannot remove them, at least protect them well with a good cover and secure them against flogging.

How do I protect the winches over winter?

Clean the salt out of them, service and grease the internals, and then cover them so nothing works its way back in. Salt is the real problem: left inside a winch it attracts moisture, degrades the grease and is the main reason gears feel stiff and notchy in spring. Once you have stripped, cleaned and re-greased each winch, an anti-mould cover keeps condensation, rain and dirt away from the mechanism through the whole lay-up, so the work you have done in the autumn is still protecting the boat when you return. It is a small, reusable step that saves repeating the full service every year.

How do I stop the interior going mouldy?

Attack it on two fronts at once: remove the moisture and keep the air moving. Empty and dry everything you can, lift cushions so air reaches both sides, open lockers, cupboards and hatches, and place moisture absorbers or a dehumidifier in the cabin to pull the damp out of the air. At the same time, arrange steady low-level ventilation through vents or a small fan, and prefer a breathable cover over a sealed tarp that traps condensation and effectively rains on the boat from within. Check and recharge or empty the absorbers on your winter visits, and mould will struggle to get a foothold.

Should I lay the boat up in the water or ashore?

It depends on your climate, your berth and how often you can visit. Ashore gives you easy access to the hull, seacocks and anodes and protects the boat from ice, but it costs yard fees and requires good support and covering. Afloat saves the lift-out and keeps the boat in her element, but it demands more frequent checks on mooring lines, chafe, seacocks and the bilge, and it exposes her to ice in colder harbours. The core lay-up checklist is the same either way; the difference is mainly in the hull work, which favours being ashore, and the mooring watch, which comes with staying afloat.

What should I check first when I return in spring?

Reverse the most safety-critical parts of the lay-up before anything else. Refit the raw-water impeller you removed, reopen the seacocks you closed, and confirm the cooling circuit is ready before you ever start the engine, since running it dry will destroy a new impeller in seconds. Reconnect and check the batteries, re-rig the running rigging and bend on the sails, and work back through your list in the opposite order to the way you laid her up. Take a slow, methodical shake-down before your first real passage, testing systems and safety gear one at a time, so anything that did not survive the winter shows itself alongside the dock rather than offshore.