Just reviewing my notes from yesterday's sea trial of a 37-foot
semi-displacement trawler.

425 HP Cummins QSB engine.

That's not a bad engine choice for a single screw boat- it can be
operated at a low rpm without loading up (thanks to computerized fuel
control), and it can ber pushed pretty hard to get more speed than one
might otherwise expect from a boat in tht category.

Fuel consumption figures are taken from the engine-diagnostics screen
installed with the Cummins QSB.

Traditonal trawler fans will recognize the performance figures at 1400
RPM, 8.2 kt at 2.4gph.
On the other end of the performance spectrum, WOT is 3000 RPM where the
boat makes 16.5 kt at 22.4 gph.

Makes a dramatic statement about fuel economy: Doubling "displacement"
speed in this boat
uses almost exactly ten times as much fuel.