Abstract: A collapsible or foldable high speed boat including a hull structure having no frames. The boat comprises a plurality of substantially triangular hinged plates joined in such a manner as to be waterproof and defining a hull structure such as that of a high speed boat. The hull structure includes a plurality of inflection points, these points being at the foremost end on the gunwale line of the stem, at the foremost end of the keel, at the widest chine line at the center portion of the hull, at the widest gunwale portion at the outermost end on the keel of the stern, and at the outermost end of the gunwale line of the stern. These inflection points can be respectively joined by lines which form substantially triangular planes. These planes define the location and shape of the various hinged plates defining the hull structure. Thus the hinged plates are arranged in a relationship formed by joining in line plural inflection points on the hull lines.