Keeping it cosy...

[Boracay]

Can anyone give me some idea of how cold it needs to get before some form of heating is needed.

It has been pretty cold in Sydney(Oz) recently - lows of 7 and highs of 17 with water temperature possibly 18 (Temperatures in degrees celsius) and it gets pretty cool inside Boracay. A little fan heater warms everything up nicely in about twenty minutes.

Boracay is a steel boat with 1" polystyrene insulation over most steel above the sole. I'll probably add a bit more insulation as time permits.

And if heating is needed what would be the most practical way, given that it is 50 years since I remember weather this cold and that it should all start to warm up in a few weeks.