A watercraft body includes a hull made of an aluminum-based material and a separately fabricated superstructure that is mounted on the hull via adjoining flange plates. To fabricate the hull, frame elements are spot-welded onto the inner surface of initially-flat hull plates or plank elements, which are then curved according to the required hull contour and assembled onto the flange plate. The frame elements are screwed together via gusset plates and transverse beams to form transverse frames, and then longitudinal seams between plank elements are continuously welded from the outside. Additionally, the longitudinal seams may be welded from the inside, for example by temporarily removing gusset plates to allow continuous access to the longitudinal seams. Additionally, stand-offs may form a spacing gap between the frame elements and the plank elements, and an adhesive may fill this spacing gap to adhesively bond the framework to the hull plating.