The aim of this work is the design of a planning hull powered with a jet engine, to get good performance with minimum installed power. The study was performed producing scale 1:1 models and a series of comparative tests between sea trials and calculations obtained from a CFD software. We evaluated the appendices effects, positive and negative misured in the real tests and in the CFD calculations. Finally we changes the shape of the hull and obtained a family of hulls believed to be the best hulls for resistence and trim valued at CFD software. It has finally realized the full scale hull fairing the better and has been tested definitely gains resistance 40% lower, compared to the hulls of departure. The result obtained was to achieve the first vessel with jet propulsion driven by a diesel motor of low power, with excellent performance.