Hello Luiz,
I don't follow what what you are saying in your comments.
The thing that stopped me from further testing/developing of the planing beach cat was that I could see it was going to be a long road, possibly without success, and I have other interests to follow.
The real world situation is, at least where I sail, when there is enough wind to plane, the surface of the water has waves on it 2 to 3ft high. Go for a ride in a flat bottom power boat and drive it into these waves even on a slow plane and the ride is very jerky and unpleasant and would probably damage the rigging of a beach cat. Drive a Vee bottom power boat into these same waves and the ride is more tolerable but the vee bottom power boat requires more horsepower to go the same speed as the flat bottom boat on flat water. Here in South Florida when the water is flat, there is no wind. The flat water situation is useless to consider because there is not enough wind to get a boat up on a plane. I'm sure the reason the seaplane has a Vee bottom is because frequently they land and take off on choppy water, real water, and they don't want to pound the bottom out of the airplane. There are many many variables to optimize on a planing beach cat hull shape by itself and I don't have a few years to devote to that.
With my brief experience with planing beach cat hull shapes, I now think the answer is a long slender planing hull shape that does not even attempt to plane to windward but runs displacement mode. Then when the boat speed doubles while reaching and going downwind with a spinnaker, the hull will climb out on a plane and really go fast when it is going along the waves or downwind with the waves and crossing them slowly. I think a narrow Vee hull shape with hard chines and lifting strakes is the way to go.
Bill