Paul Fritz wrote:
Doesn't seem unusual to me at all. At around 2500 rpms is about where
mine drops off plane and essentiallly plows water.....much of the energy
produced by the engines is being used to push water out of the way, not move
the boat forward. At rpms around 1500, more energy is moving the boat
forward than pushing water,(less wake for example) and the same is true at
3000 with the hull on plane.

A bit of physics here... with the hull on plane, the energy required to
lift the boat is coming from the engine.

It's possible that gas mileage for light planing hulls has improved in
recent years. But the efficiency curve still isn't going to go backwards
to any significant degree, and adding any load to the boat is going to
make the curve steeper (ie higher penalty on mileage at higher speeds).

Motorboaters deny it to their dying breath, but it's like arguing
against gravity. Speed costs. Sorry to be the bearer of bad news.

Fair Skies
Doug King