Laying Up for Winter: What Surveyors See

It is a still morning at the end of October. Mist is lifting off the river, the hoist (the wheeled frame that lifts boats out) is busy, and owners walk between the boats on the hard (the yard's area for boats ashore) with flasks and folded covers. Laying up has begun: the autumn work of putting a boat to bed for the winter.

Come spring, a boat tells the story of her winter: to you first, and to any surveyor who steps aboard. It shows in five places, each with a job you can do now or hand to the yard as part of a winterising service. Here they are for a boat ashore, then for one left afloat, coast or canal. A careful lay-up is time well spent: she comes back in spring ready to go.

1. Water Left to Freeze

Water expands as it freezes, with force enough to split a pipe, a pump or the calorifier (the hot-water tank, heated by the engine or by shore power, the mains hook-up at the berth). After the hard winter of 2009 to 2010, one insurer reported a high number of claims for split and fractured pipes.¹

Drain the domestic water system: the tanks, pipes, pump, calorifier and shower. Switch the water pump off and leave the taps open, so no water is trapped.² Flush the toilet with fresh water and pump it dry.³ A heating circuit with radiators needs draining too,⁴ unless it holds antifreeze at its maker's strength. Never put car antifreeze in the drinking-water system.

The engine is a job for its manual or the yard. Most inboard engines hold coolant, as a car does, cooled in turn by seawater or river water that is drawn in and sent out with the exhaust (the raw-water side). The raw-water side is drained or filled with antifreeze, and the coolant's strength is tested. Some smaller engines are cooled by raw water alone, so the manual's steps matter all the more. Many owners also change the oil, since used oil carries acids, and fill the diesel tank, leaving a little room, to limit condensation.³ Then hang a label on the engine saying what has been done, for recommissioning in spring.

In spring, frost shows as a split calorifier, a cracked pump or water strainer, or a stain where something wept.

2. Batteries Left to Run Flat

A battery left to itself slowly loses charge, and a flat battery freezes far sooner than a full one. One battery maker puts the freezing point of a flat lead-acid battery at about −3°C, while a fully charged one copes with far colder than a British winter brings. Freezing can crack the case and buckle the plates inside.⁵

Charge the batteries fully before you leave her, then keep them charged: a marine charger on a float charge (a gentle charge that holds them full), where the yard allows shore power, or solar, or a visit each month with a charger.² Ashore, taking them home works too. If they are lithium (the label will say), follow the maker's rules for storage and for charging in the cold. If a charger or dehumidifier is left running, make sure the wiring is sound and the yard agrees.⁴

In spring, flat batteries mean the bilge pump, lights and instruments cannot be tested on survey day.

3. Damp Below, and the Cover

A cover keeps the weather off, and a boat still needs to breathe beneath it. Take the cushions, sails, sprayhood and other canvas home or to a dry store, and leave lockers and drawers ajar.⁴ Weatherproof vents let air move through the cabin, and are worth fitting if she has none.³ A cover over a frame or the boom sheds rain and lets air pass underneath. Tie it to the boat itself, never to the stands, which a cover tugging in a gale can disturb.⁴ Before you lock up, turn the gas off at the cylinder.

In spring, damp shows as mould on the headlining (the lining of the cabin ceiling), stains under windows and hatches, and swollen joinery. Much of it cleans off. A stain under a deck fitting can mean a leak, and is worth tracing.

4. How She Sits Ashore

A yacht ashore usually rests her weight on her keel, on blocks, and the stands (adjustable props with pads against the hull) keep her upright. A motor boat usually sits in a cradle or on blocks. Setting her up is the yard's skilled work. Your part is a look on each visit, every month or so and after a gale: pads snug against the hull, and nothing tied to the stands. If anything has moved, tell the yard and leave the stands to them.

Whether the mast comes down is a question for the yard and your insurer. Down has a bonus: the rig (the mast and its wires) can be inspected at ground level.⁴

5. Drains and Seacocks

Seacocks are the valves on the fittings that pass through the hull. Work each one open and closed. Ashore, lay-up is a good time to grease them as the maker suggests, so they turn freely in spring; that is never a job for a boat afloat. If one is stiff, leave it for the yard to free. Set them as your yard recommends: some owners close them, others take the hoses off and leave the valves open to drain and air.³ Either way, leave no water inside the valve, where frost can crack it. Some valves have a drain plug for this. Then hang a label on the wheel or tiller listing what to check before launch, for you and for whoever launches her.⁴

The cockpit drains carry rain overboard. Leaves block them, and the water pools and freezes. Clear them on each visit.²

In spring, a seized or frost-cracked seacock goes in the report. Our posts on through-hull seacocks and on sterngear (the propeller shaft, its seal and its bearing) are written for surveyors, and show what they check.

If She Stays Afloat

Many yachts and motor boats winter afloat in a marina, and most narrowboats stay on the water. The water, battery and damp jobs are the same, and ropes take the place of stands. Afloat, add these:

• Seacocks. Close every one you do not need, apart from the cockpit drains. A strainer, pump or hose below the waterline that frost has cracked can let water in when the ice thaws. If one will not close, tell the yard straight away.
• Rain. On each visit, clear the cockpit drains (on a narrowboat, the drains at the stern and in the well deck at the bow) and pump out any rainwater. Visit after floods, gales or long rain, too.²
• The bilge pump. If she has an automatic bilge pump, a float switch starts it when water rises. Test the pump and its battery before you leave and on each visit. If she has none, one is worth considering.² Ask the yard or a marine electrician whether the pump still runs with the battery switch off.
• Ropes. On rivers and canals, keep them secure but slack enough for the water level to change.² In a marina with floating pontoons, double the lines for winter, protect them from chafe where they pass through a fairlead, and check the fenders.
• Shore power. If she stays plugged in all winter, ask the yard whether she has a galvanic isolator. It helps protect the anodes (the metal blocks that corrode in place of the hull's fittings) and, on a steel boat, the hull.
• Staying aboard. Heating in place of draining works only while someone is aboard. A weekend boat is drained between visits, unless the marina agrees to a heater made to be left running. Never leave a stove alight with no one aboard. Keep the fixed vents clear, and test the carbon monoxide alarm and check its expiry date. On inland waters the Boat Safety Scheme has required one on boats with cabins since April 2019.⁶

On a Narrowboat

• Water and heating. Drain the tanks, pipes, pump and the calorifier's domestic side, switch the pump off and leave the taps open. Drain a central heating circuit too, unless it holds antifreeze at its maker's strength.
• Engine cooling. Many narrowboat engines are keel-cooled: their coolant runs through a tank against the hull, and no canal water comes in. The Canal & River Trust suggests testing the antifreeze strength, and acting if it is under 50%.² A weak mix is best strengthened or renewed with the coolant the engine maker specifies.
• The stern gland. Where the propeller shaft leaves the hull, grease keeps the water out while the boat sits still. If she has a stern greaser (a screw-down grease cup in the engine space), give it a turn before you leave.²
• Damp. Steel boats gather condensation in the cold, so take soft furnishings to a warm, dry place.²

Narrowboats seldom come out of the water for the winter. If a hull survey is due, the natural time, within your insurer's timescale, is when she is next out for blacking (the black protective coating on the hull sides, up to the rubbing strakes). Ask the surveyor to come once the hull is washed and before the new coat goes on.

Your Insurance Over Winter

Read your policy's winter terms before she is laid up. Some have a laid-up period or status, when she is not used,¹ and some ask for her to be ashore by a certain date, so check before she winters afloat, and tell your insurer if the lift-out slips.⁴ Frost damage is not covered by every policy. Where it is, the insurer commonly expects the water drained and the engine winterised as the maker recommends.¹ Keep the yard's invoice for the winterising, or a dated note and photos if you did it yourself, and ask your insurer how your own policy works.

A Boat Ashore Is Well Placed for a Survey

If your insurer has asked for a survey, a boat already ashore saves booking a lift-out, and any work below the waterline that the survey recommends can be done before she goes back in. An insurance survey records the boat's condition and value for your insurer. Insurers often ask for one when you first insure an older boat, and at intervals as she ages; each sets its own rules.

Three things help on the day:

• Survey date agreed with the yard or marina
• Keys, batteries charged and lockers cleared
• Paperwork to hand: registration, service history and any earlier survey

Tell the surveyor she is laid up, and ask the yard to have the cover off, or ready to come off, on the day. Book the survey before new antifouling (the paint that keeps growth off the hull) goes on. Pads and blocks hide parts of the hull, and the yard may move them one at a time. A winterised engine and drained systems may not be run or tested. How much of the rig an insurance survey covers varies, so ask your insurer and the surveyor. On a fibreglass hull, moisture readings (which look for water in the laminate) depend on how long she has been out and on the day's conditions. The report will say what could not be seen or tested. Our boat surveys page sets out what each survey is for, and insurance surveys and pre-purchase surveys explains how the two differ.

If a survey is due, find a boat surveyor near the yard who offers insurance surveys, and book it while she is ashore. For a boat on the canals, a narrowboat surveyor can fit it around her next blacking. A free account keeps a shortlist of surveyors, a private note on each and a list for survey day, on iPhone, iPad and Android.