Everything you do, or fail to do, on the last weekend of the season comes back to find you in spring. The boat I keep cleanest over winter is not the one I fuss over in March, it is the one I shut down properly in October. A friend who skips the autumn work spends every April flushing stale water tanks, chasing mould off the headlining and bleeding an engine that sat with half a tank of fuel breeding water. I spend April sailing. Same boat, same marina, six months earlier is the only difference.
Lay-up is the unglamorous half of seasonal boating, and in France it carries a couple of local wrinkles that catch visitors out. Here is the way I work through it, whether the boat is going ashore in a yard or staying afloat on its winter lines.
Get the timing right first
Decide early whether you are hauling out or staying in the water, because each has its own deadline. If you are coming ashore, the lift slot is the bottleneck: the good French yards fill their autumn calendars by midsummer, and turning up in October expecting a lift is how people end up paying weekend surcharges in November gales. We cover that scramble in our piece on when to haul out in France, and the headline is simple: book the slot in July, do the boat around it.
If the boat is staying afloat, the timing is gentler but the line and chafe work is more important, because nobody is checking it for months. Our guide to leaving the boat afloat over winter in France goes through the mooring, bilge and insurance side that this checklist assumes you have read.
The engine: do this on a warm day
Engine winterising is the job most worth doing carefully and least worth rushing. Do it before the last sail rather than after, so you can run everything warm.
- Change the oil and filter before lay-up, not in spring. Acids and moisture left in the crankcase over a cold winter pit bearings and other internals. Run the engine to warm it, then drain it hot so the muck comes out with the oil.
- Fill the fuel tank to around 95 percent with clean diesel and add a stabiliser. A full tank leaves little air for condensation, and condensation is what breeds the diesel bug that clogs filters and ruins a spring.
- Protect the cooling system. Circulate non-toxic propylene glycol antifreeze through the raw-water side, rated well below the lowest temperature your region sees. Avoid automotive ethylene glycol, which is toxic and ends up in the water.
- Check or replace the impeller, and consider pulling it out to relax the rubber over winter, marking the housing so you remember it is missing.
Even on the mild Mediterranean coast, where hard frost is rare, the antifreeze step matters: a single cold snap can split a heat exchanger or a pipe, and the repair dwarfs the cost of a few litres of pink fluid.
Fuel, water, gas and the wet systems
Drain and dry anything that can freeze or stagnate.
- Freshwater tank: drain it, or sanitise and leave it full to a strength that will not stagnate. A half-full tank that sits all winter comes out smelling foul.
- Pipes and the calorifier: drain low points if frost is a real risk where the boat lies.
- Heads and holding tank: pump out, flush through with fresh water, and add antifreeze to the bowl and the lines. A frozen, fouled head in spring is the worst job on any boat.
- Gas: turn it off at the bottle, and if you are leaving the boat unattended, consider removing the bottles altogether. Check the regulator and hose dates while you are at it.
Damp is the real winter enemy
In a French winter the boat does not usually freeze solid, it sweats. Black mould on the headlining, musty cushions and corroded electrical contacts are all the work of trapped moisture, and they do more damage over a quiet winter than any storm.
- Lift every cushion on its edge so air moves under it, or take the soft furnishings home.
- Open lockers, the heads door, the engine box, everything that traps still air.
- Leave passive vents cracked and, if you have shore power and the boat is afloat, run a small dehumidifier or a low-wattage tube heater to hold the damp down.
- Empty the food lockers completely. One forgotten bag of flour feeds an entire winter of weevils.
The damp battle is the same whether you are aboard or the boat is empty, and it is the single biggest reason a winter-lived-in boat smells better in spring than an abandoned one. Our look at winter liveaboard life in south France covers the heating-and-ventilation balance in detail, and the principles apply even to a boat nobody is sleeping on.
Batteries, security and the small stuff
Top the batteries up and either leave them on a smart float charge if you have reliable shore power, or take them home and trickle-charge them somewhere dry. A flat lead-acid battery left over winter sulphates and may never recover.
Strip the deck of anything that flogs, holds water or invites theft: remove the sails or at least the headsail, lash the halyards off the mast so they do not slap all winter and drive the neighbours mad, take the danbuoy and loose gear below, and dog down the hatches. If the boat is ashore, check the cradle pads and that the boat is chocked level so water drains off the cockpit sole.
Ashore versus afloat: the jobs that differ
Most of this checklist applies whichever way you lay up, but a few items split sharply between a boat on the hard and a boat on its winter lines, and getting the split wrong is where damage creeps in.
If the boat is ashore, the priorities are drainage and support. Make sure the cockpit drains run clear and the cradle or props hold the boat slightly bow-up or otherwise tilted so rainwater sheds rather than pools. A blocked cockpit drain under a winter tarpaulin can fill the cockpit and find its way below, and a boat left dead level can collect standing water that freezes and works into the gelcoat. Check the cover does not chafe and is not a sail in a gale, because a loose tarpaulin in a winter blow does more damage than no cover at all.
If the boat stays afloat, the priorities are lines and through-hulls. Every mooring line gets doubled and protected against chafe, because nobody is watching it for months and a single line wearing through in a January gale is the classic afloat-winter disaster. Close every seacock that does not need to stay open, leave the bilge pump live with a fresh battery feed if you can, and arrange for someone to check the boat after every serious blow. The afloat boat is comfortable and cheap to keep, but it punishes neglect harder than the boat on the hard.
Foreign owners: the paperwork too
Leaving a foreign-flagged boat in France over winter is mostly the same lay-up as anywhere, with a thin layer of admin on top. Confirm your insurer is content with the boat unattended and laid up at the named location, leave reachable contact details with the capitainerie or yard, and keep your ship's papers and proof of VAT status in order. We set out the specifics in our note on the foreign owner hauling out in French boatyards, worth a read before you fly home and forget about the boat for five months.
The honest reward for a careful lay-up is a dull spring, and a dull spring is exactly what you want. No bug in the fuel, no mould on the headlining, no foul tank, no seized seacock. You do the unglamorous work on one warm October weekend and you buy yourself a first sail in April that is nothing but pleasure. Skimp it, and the boat collects the debt with interest the moment the weather turns nice again.
