Planing craft are the most common boats used all around the world for small commercial, military and pleasure craft. Hulls available for planing craft are many, differing for geometry, shape and dimensional ratios. Despite of that, there is a lack of experimental data on these hulls and there are no effective and user-friendly tools, available for Power and Resistance Assessment in the Preliminary Design Phase, except in the case of very simple hull geometry. The goal of this book is to try out a new effective and robust tool useful to the small-boat Naval Architect, to attack the Resistance Assessment Problem for a planing craft in calm water during the Preliminary Design Phase. Rem tene, verba sequentur.