I would avoid an aircooled diesel
in a sailboat. I have seen a few over the years and the heat build up is terrible, as is the noise
. They were popular in small north sea fishing
boats because they were cheap
to buy and could keep the cabin
warm on cold trips.
The advantages of today's fresh water cooling systems is that we get to run the engines at the correct temperature to get near complete combustion for EPA specs and CE specs. The salt water
(raw water) side of the system allows us to use reinforced rubber hose for the exhaust which is easy to fit and because the temperature is kept low, there is little or no fire risk.
If you are serious about this boat, allow for an engine replacement in your offer.