Prepping your boat for winter

Compared to other parts of the world, winter in Australia is quite mild. We do not expect our yachts to be iced in or frozen over, but we can expect some pretty extreme winds, just like two weeks ago when 80kts was recorded at Tasman Island! Generally we do not use our boats as much in winter than in summer so its a good idea to give the boat, your mooring or marina berth, and equipment a once over to ensure they will be in tip top condition when the warm days return.  Richard Hewson from Salus Marine Survey Tasmania has a few tips for getting your boat or yacht ready for winter.


Check your mooring or marina berth lines and chains to make sure there is no chafe, shackles are done up tightly and moused and the vessel will not touch the dock in strong winds. If you don’t plan to use your sails, remove furling sails from the furler, and lash your mainsail so if the bag un-zipps itself your mainsail wont flap in the breeze. The biggest cause of damage to yachts in marinas and on moorings is due to unsecure sails!


Especially during colder months, mould is the first and foremost enemy of the idle vessel. Where moisture and condensation are harboured you can virtually shave the evil spores off cabin walls and cushions after a few weeks, so a little autumnal ‘spring’ cleaning goes a long way. Wipe over the interior with a mixture of vinegar and water to remove any of the unwanted mould pours.

Empty out your fridge and freezer, turn them off and give them a good clean.  Best to take any beer off the boat or drink it before you leave as beer can explode and make a mess attracting mould.  In particular the XXXX cans seem to explode easily just by the boat rocking on a mooring.

Valuables like electronics, wet-weather jackets, PFDs, inflatables and auxiliary outboards are all best stored in the garage. Removing biminis and dodgers prevents them being damaged by winter storms.

Take the time to clean and treat rust wherever it lurks – better now than wrestling corroded bolts and broken fittings in next summer.

To encourage cabin circulation, leave the bunk mattresses upright and locker covers and cabin doors ajar. Close off the seacocks and get the various sumps as dry as possible. Then scatter some moisture absorbers throughout the interior.

A dehumidifier is a wise investment for marina-berthed boats, although fires are known to have been triggered by electrical faults on shore-powered 240V devices. You need to be sure that the dehumidifier is well secured and has adequate drainage.

Draining the water tanks is advisable but before doing so, flush the head copiously with fresh water and vinegar.  Rinse caked-on mud off the anchor and chain, then hose out the scuppers and cockpit drains.

It pays to purge the holding tank as well – after which a splash of deodoriser should suffice, although in frost-prone regions some owners run non-toxic antifreeze through the intake lines, macerator and discharge hose.


When it comes to long-term fuel storage, particularly diesel, there’s a Catch 22. Popular wisdom holds that you should fill the tanks to limit the space where condensation collects, however there’s a risk of it going stale and being wasted.

Fuel companies have reportedly taken some of the old additives out of diesel to pass emission regulations, reducing shelf life to less than a few months in some cases. Leaving tanks empty, conversely, increases the opportunity for algal contamination. Treating the fuel with an after-market stabiliser is the best solution. After adding it, run the engine for around 10 minutes to circulate the stabiliser.

Portable outboard petrol tanks can sweat beneath boat covers so are best left in a shady corner of the shed. If you can disconnect the fuel line then do so; rubber eventually hardens when it continually cycles between hot and cold.


Generally most diesel yacht engines will look after themselves and there is no need to winterise them as such, but this is a good opportunity to check the engine lubrication, grease nipples, and give the engine a wipe down from any salt build up that may have occurred during the season when you were pushing the boat a little, and a spray and wipe of WD40 will give a film of protection for any winter moisture.

Petrol engines on the other hand require a bit more love.  Outboard engines flushed with fresh water and fuel drained

To further prevent moisture from seeping into the engine you can plug the exhaust and possibly the air inlet with tape or a wooden bung.

Gensets can be added to the maintenance list if you’re concerned about cold. Treat them the same as a diesel, although the metal components in the electrical motor do suffer from prolonged exposure to salty air.

Because marine air-conditioners use water to cool the condenser, manufacturers recommend forcing water out of the system with pressurised air or, better still, pump antifreeze through.

As is often the case, the best maintenance is use. On a calm winter’s day it’s worth running your motor and gear under load (in gear), if only for an hour or so. Idling the diesels in the pen is not ideal since carbon builds up.


Make sure when you leave your boat all the circuits and switches are turned off and your battery charger or solar panels are charging the batteries.  If you don’t have a solar set up, its worth getting a cheap unit from the local cheap auto distributor and wiring it in for the winter months.  Even with shorter days and lower solar irradiance its better than no charge at all. If your boat is small enough, disconnect the batteries and take them home to provide a trickle charge. Smart marine chargers are recommended over automotive units provided you ensure the correct battery type is selected.

Lead-acid batteries prefer temperatures around 25°C and their capacity plummets as the mercury drops below 15. If left discharged, flooded batteries can freeze, and some electricians also advise against storing batteries directly on cold cement floors.

At the other extreme, electrolyte levels can boil dry with repeated charging and minimal usage. There’s the added threat of excessive gassing in lead-acid batteries, releasing hydrogen. It’s no coincidence that ice-monitoring stations in the Arctic use sealed batteries that hold the electrolyte in glass mats, preventing cracking and leakage. Gel batteries are better still, though dearer.


Check rudder glands, transducers, skin fittings and deck fittings for leaks.  Make sure you are aware of any leaks and preferably attend to them.  If your bilge pump is on auto, make sure its not going to flatten the battery.

Physically check the bilge pumps are working – if the hoses, connections, or wiring look marginal then fix them.

Close all sea cocks below or close to the waterline.  Make sure your bilge pump valve and any scuppers (both should be above the waterline) remains open or make an alternative arrangement.


If you’re giving your boat the cold shoulder for weeks on end let a mate and the marina manager know and ask them to check on your boat.  It is a good idea to leave your phone number on your companion way, and make sure the local marine and safety agency M.A.S.T has up to date details.  If your really tech savvy you could also wiring in your own CCTV or  Yacht-Sentinel system, which sends updates to your mobile to warn of possible electrical problems.


Fitted full boat covers are an awesome addition and can save hours of polishing or sanding and varnishing  provided they are well fitted.  Poorly fitted covers or the good old blue tarpaulin will do more damage than good, with even the smallest flap chafing its way thorough your gelcoat or varnish on a windy night.

For trailer boat owners its simple.  Fit the cover, don’t park under trees. and store the hull with the bow raised so water will drain.  Make sure the cover is tight to prevent local wildlife taking squatter rights. And speaking of covers, trim down the motor to empty the lower unit and, once dry, seal it with a plastic bag.


  • Sea cocks closed
  • Cockpit drains and scuppers clear
  • Fuel off
  • Gas Off
  • Electrical circuits off
  • Batteries charging
  • Halyards and sail covers tight and secure
  • Check mooring secure

Finally the admin.  Look around at the other boats moored in your vicinity.  No doubt most of them will not have been checked for the last few months so make sure you check yacht insurance is up to date incase one of those un loved ladies comes detached from her moorings and scratches your duco.  If you need an insurance survey for your boat and yacht in Tasmania, please feel free to give Richard Hewson at Salus Maritime and Marine Survey a call.

See you on the water.

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