How can I winterise my boat myself, and what maintenance steps should I follow?
I'm laying up my boat over winter and would like to do the servicing myself. What should I tackle first, and how does the checklist change if I leave her afloat rather than lift her ashore?
Answer
You can winterise your boat yourself by servicing the engine, protecting every water circuit against frost, maintaining the batteries and keeping the hull and cabin clean and dry, with air circulating. Start with the engine handbook and decide whether to store afloat or ashore, as this determines the cooling-system procedure, seacock positions and which electrical circuits must stay on.
Engine and fuel system
Establish whether your engine uses direct seawater cooling or a closed coolant circuit with a heat exchanger. A heat-exchanger engine has two separate circuits to protect. Before buying materials, check the handbook for drain points, antifreeze specification and requirements for your model.
- With a proper cooling-water supply connected, warm the engine and change its oil and filter using the specified grade and quantity. Inspect belts, hoses, clips and engine mounts.
- Service fuel filters and drain water from the separator into a suitable container. Investigate excessive water or black sludge now rather than leaving it until spring.
- For a heat-exchanger engine, check the closed-circuit coolant strength with a tester suitable for that coolant. Replace the coolant if its service interval has expired.
- Protect the seawater circuit using the manufacturer's draining or antifreeze procedure. Where bucket-feeding is specified, close the intake seacock, connect the intake securely and keep the supply flowing while the engine runs briefly. Collect the exhaust discharge.
Antifreeze at the exhaust does not prove that every passage is protected, particularly on directly cooled engines with thermostat-controlled flow. Never run the impeller dry. Reconnect the intake hose afterwards and leave a conspicuous reminder of the seacock's position.
Fill a diesel tank to its normal safe filling level, leaving expansion space, or empty it completely. Empty portable petrol tanks into approved storage. For fixed petrol tanks and injected engines, follow the handbook's storage procedure, using stabiliser or fogging only where specified. Flush an outboard with fresh water as instructed, check gearbox oil for water contamination and store it in the specified position, usually upright so it drains.
Drain and frost-protect water systems
Work through the freshwater plumbing, toilet, holding tank, deck shower, washdown pump and any air-conditioning circuit. A forgotten shower mixer or pump strainer can split even with the main tank empty.
- Empty freshwater tanks and drain the calorifier once cool, following its instructions. Isolate its electric heater so it cannot operate empty.
- Open hot and cold taps and drain low points, filters and pump housings. Bypass the calorifier if required before introducing antifreeze.
- Where complete draining is impossible, use propylene glycol antifreeze intended for potable-water systems. Draw it through each outlet at the product's specified concentration.
- Pump out the holding tank, rinse it and protect the toilet pump, bowl and discharge plumbing according to the toilet manual.