Abstract: In this study, a new method to compare rebuilt surfaces of hulls of sailing yachts is presented. In particular, the considered rebuilt surfaces are created through classic reverse engineering approaches. The new method has been developed by means of Grasshopper, a free generative algorithms editor that can be used as plugin of Rhinoceros, one of the most widespread free-form modelling software. In particular, two different algorithms have been developed: the first one allows controlling the quality of the rebuilt surfaces, the second one, instead, allows to measure the deviations between the original CAD Model and the rebuilt surface of the hull. A case study related to the hull of a small sailing yacht is also presented. The obtained results have demonstrated the efficiency of the new proposed low-cost method.