[CaptPKilbride]

I had always thought that the major difference between the two was in their resistance curves?

I percieved that a semi-displacement hull would have the sharp transom, allowing water to flow cleanly off the transom, and with more and more horsepower the hull would go faster to a certain point. This point being faster than a displacement hull with its theoretical hull speed limitation (1.44 x square root of LWL). Once the semei-displacement hull reached this "sweet Spot" in it's resistance curve, it takes exponentially more horsepower to produce speed gains given the same displacement.

And conversely, I thought that true planing hulls would produce more linear speed increases with increased horsepower (again given the same displacement)

Am I on the right track? Or was my perception off base.

By the way, Mr. Blount, I love what your company has done with the hull design and performance of the Rybovich sportfishing yachts !!