The Wiebel boat has four planing pods. See the image. Why?
Well, the simple answer is, the boat has four planing pods because a car has four wheels. It provides maximal stability and a minimal contact with the water.
Three may also work, but four provides a good roll axis on both the left side and the right side of the boat. Another way of putting it is that the boat needs a stepped hull on both sides, which results in four planing pods.
