Winter sailing - protecting engine from frost / freezing

[dunedin]

The sea water surrounding the hull rarely reaches freezing temperatures and acts a s a blanket around the hull . Put a thermometer
in your engine space for the winter and you may be surprised at what it shows. Engine freezing may be the least of your problems however
this might not be the case regarding fresh water systems elsewhere in the boat.

If you use a gardeners thermometer then it will actually record the lowest temperature it is exposed to.

Our boat has been afloat the past 5 winters or so - including periods with -10C outside temperature - and so far without issues (unlike the year ashore when did have freezing issues). This is one reason why we stay afloat, as some great sailing and far less problems.
We use two tube heaters on thermostats - and simply depressure the domestic system (by opening tap with battery off) before leaving. The long thread on winterising seemed a lot of extra work, but necessary when on shore

 

[laika]

I've stayed in the past 3 winters. Having spent the summer out of the water I hope to launch again in the next few weeks Sea temperatures in the solent don't really dip much below 8 degrees. Earlier this year I could barely turn the instruments on my fingers were so cold but I think the lowest I've seen in Portsmouth harbour is seven point something. Look at any average sea temperature chart and you'll see things get somewhat colder in the north sea approaching the Dutch coast. Obviously a balmy 8 or 9 degrees enveloping the hull stops things getting too frozen but not necessarily warm enough to type in the saloon.

Sea temperature gauge is a much underused instrument. It's a wonderful thing to check daily when sailing from france to the caribbean in november/december...