I think it's more about surface tension, adhesion and low/high surface enrgy interfaces. A displacement hull has to push aside an amount of water equivalent to that it displaces at the speed of motion. The water 'wets' the surface to some degree and adheres viscously impeding the hull's motion. The water moves out of the way as fast as the hull goes, up to a point, at which the hull begins to plane. At that point the water is no longer 'wetting' the hull surface. So planing happens when the hull moves swiftly enough to exceed the capacity of water to move out of the way. Note that this is a pretty good analogy to subsonic and supersonic flight.

But there are other ways to reduce surface wetting, certain surface coatings for instance. Low surface energy coatings cause water droplets to bead up rather than spread out into a thin film, implying poor wetting and thus adhesion.

Jimbo