My 1971 C&C
custom, 37' trawler
with a single Perkins
HT6-354, 165hp and 20,000 hours on it runs at 1.6US gallons per hour at 1600RPM that takes it from Toronto to Dry Tortugas
and back on less than 800 gallons.
Don't get focused on a specific brand of trawler, try to find a one-off or a lesser known brand with a real displacement hull
as these are much less expensive to run than the psuedo trawler Monks, Grand Banks
Try to find one with a Lehman
which were designed for lower RPM
Don't be afraid of a turbo, mine went 20,000 hours before rebuild
. Just get a good survey
and a good diesel mechanic
to go over everything.
A brand name (real) trawler hull
such as a Nordhaven or Krogen is financially out of reach according to your self description.