Preparing your boat for any period of standing or floating idle, need not cost the earth but its’ well worth the effort.
1.) Use it! The best way to winterise a boat is to use it. A boat contains a multitude of systems that hate inactivity - particularly the engine.
Diesel engines may be complicated and costly but are absolutely vital for safety and enjoyment, and need to be understood and looked after. There are plenty of other items that would benefit from winterization but if you only do one thing, do it on the engine.
2.) General engine cleaning and observation should be first on the list of things to do. Shine plenty of light, use a mirror on a stick or a digital camera to see under and behind things - especially all the elements of the exhaust. Once you’ve finished changing oil, filters and coolant, dry the bilges completely beneath the engine, to prevent corrosion and if necessary, paint them white to highlight any leaks and drips in the future.
3.) If your boat is being lifted out for the winter you should fill your fuel tank to the brim to prevent condensation, which in turn prevents the growth of diesel bugs.
Before topping up your tank, take the opportunity to use a bit of fuel treatment to kill off any diesel bug that might already be in the tank.
4.) Change the engine oil and replace the oil filter before leaving your boat for the winter. Leaving the old oil contaminated with the acidic by-products of combustion inside the engine block will shorten the engine’s life. And, while repairs to auxiliary components won’t necessarily break the budget, a neglected oil system will cause expensive damage.
5.) Before leaving the boat ashore in the winter check the gearbox or outdrive oil and replacing if it looks cloudy or milky.
6.) Most diesel engines use a combination of raw water and freshwater cooling - both of which need attention when winterizing. Drain the cooling system before hauling out, by disconnecting a hose from the circulating pump (unless there is a dedicated tap or plug), then refilling with a strong solution of fresh antifreeze. Run the engine to fully circulate the new solution. Simply draining the system is unlikely to remove all the water inside, which may then freeze and cause damage over the winter.
7.) Removing the air intake filter once ashore in the autumn and stuffing the intake with an oily rag can prevent it rusting inside. You could squirt a little oil into the intake and turning over the engine (without starting) to distribute it over the cylinder walls.
8.) Where possible, keep batteries warm and dry over the winter, fully charged or topped up at least every four to six weeks. Batteries left uncharged for long periods may need to be replaced completely.
If you’re unable to remove batteries, the best advice is to leave them fully topped up and regularly recharged, as full batteries are less likely to freeze in sub-zero temperatures. Disconnect the batteries from the rest of the electrical system and clean and grease the terminals.
9.) Relax or remove all belts and protect the drive wheels. Rust on these can chew up a belt very quickly in the new season.
10.) Make sure the boat is angled bow upwards slightly to enable rain water to run off immediately from covers, decks and cockpit.
Covers should keep water out but allow air to circulate. Proper through-draught will prevent condensation which leads to dry rot, mould and corrosion (especially if left for more than a single season).
11.) Store all linen, clothing, blankets, curtains, etc. ashore – washed and dry. Prop the fridge door open – mould will form in less than a week if left closed. Ensure through-ventilation. Leave cupboards and drawers open; prop up bunk cushions, leave under-berth locker lids open. Get circulation into every possible nook and cranny.
12.) Ensure tight-fitting covers for deck-installed electronics and consider spraying behind electronics with water-repellent silicone. Check your navigation lights – the range, bearing, wiring and condition of covering (is it crazed or damaged)?
This list is no means exhaustive but it will give you a good idea of the things to consider when putting your boat to bed for winter.