I was rereading my notes from last season and was reminded of a question that came up. We have done a lot motoring along French canals in hire boats. They all had diesel-fired
water heaters. Universally the
water would stay hot enough that we could have a warm to hot
shower the next morning without firing up the
engine again. But none of the sailboats we chartered this season (in the PNW) provided more than tepid water after any significant time had past.
How do the hot water
tanks on a typical sailboat
work? I do know the after berth above the water
heater benefited from the heat produced, but the
insulation didn't seem to be there to keep the water hot. Is it a matter of size? The
canal boats tended to be 40-50 ft. I will say the water was generally way hotter on the sailboat after the
motor was shut off: hot enough to melt a plastic pop bottle. Never had that problem in
France. So probably completely different systems...
So what does one need to know about hot water on board?