John Deere or Cummins

>I suppose it all comes down to how much power is required to push this vessel at it's hull speed, and or most efficient speed.<

Probably not , usually sail boats are interested in hull speed but few marine motorists chose to operate there.

The reason is slowing about 1K can frequently save 1/2 the fuel burn.

Most cruisers will set up to load the engine well at a very good percentage of the 24/7 curve at cruise RPM.
If the engine can operate at 70 hp at 1400, and the boat needs 60 at SL 1.15 , thats where you want to be.

The shorter operating hour graph can be used for heavy weather when higher HP is required to maintain speed.
Usually high speed in a sea state results in severe motions the operators find uncomfotible , and perhaps dangerous.

The difficult boat to engine is the oxymoron , fast trawler, that may want 20K once or twice a year .

Then the recreational ,short time , engine load is used for the top speed desired and a compromise is required the other 98% of the time when displacement cruising.

Usually it only calls for lighter less efficient loading at higher RPM , so the vessel might cruise at 1800 rpm where it could put out say 110 hp , but the same 60 is needed to move the boat. A fuel map can help these decisions , prop load fuel burn is useless.

The engine size , drive and hull should match the owners desirements , although efficient fast and slow may be wanted , a compromise is required.


Most rec boats will not pay the bucks for a CPP or other fancy way to attempt to compromise .

 

Fred,
I have to agree with you, and everything is a compromise these days, there again we must go back to my original post, the vessel is a troller, used for fishing, using west coast style tuna / salmon gear, maybe I should have said that to start with? Other then just describing a troller and assuming people knew what that was, and again I agree with you

John