Higher HP diesel?

[Nomad Willy]

Powering a hull correctly and loading the engine correctly is the big question unless it's a passagemaker. Not maximum efficiency. Over the ranges we're talking about here there is probably less than 5% difference in fuel economy. Most people won't need to be concerned about it.

 

[Joe Donovan]

Appropriate power for Seapiper 35

Here is the power/rpm/fuel consumption (in litres so divide by 4) for the Seapiper with the Beta 85 turbodiesel. Apologies that it is cut off. I have Hull No. 10 under construction and got this from the designer/builder.

At 2000 rpm she is supposed to do about 7 kts, burning about 1.5 gallons/hr.

Max rpm is supposed to be between 2800 and 3000. I would think that that would be enough "spare power" given the semi-displacement hull which, incidentally, was inspired by the "Sea Bright" Jersey surf rescue boats!