Steve 1 is right, most steps are poorly designed. When I look at the steps in my boat and those on some of the others I wonder if they heard of a wind tunnel much less tested in one.
From Ocke Mannerfelt:
Most of the stepped hulls currently in production were originally designed as non-stepped V-hulls. Steps have often been added to these original designs as an afterthought, and then built into existing molds. This is not the case with the B-28. From the very beginning, the B-28's transverse steps were engineered as an integral part of the boats running surface and have been strategically placed to serve specific purposes and provide excellent balance. The first step sets the angle of attack of the hull, while the second step controls the waterflow to the aft section of the hull, which carries most of the boats load. The steps are also carefully shaped to introduce air into the water under the boat. The resulting air bubbles act as ball bearings, providing a faster, less resistant running surface. Planing over a bed of foaming water reduces friction, increases speed, and benefits fuel economy.