Abstract: A folding kayak includes fore and aft subassemblies which are joined together and are covered by a water-impermeable skin to provide a watercraft with the favorable attributes both hard shell and skin on frame kayaks, with none of the disadvantages. In addition, one or more hydraulic adjustment mechanisms provide the kayak with characteristics of a plurality of different rigid body kayaks, with different operational characteristics, suitable for open-ocean or closed-water environments as desired. Ribs which are part of the kayak assembly have a relatively flat profile, making the kayak perform more favorably in adverse water conditions, and also giving the kayak some resilience and flexibility when encountering obstructions in the water. In one aspect, the kayak subassemblies may be joined, at least in part, by corrugated splines. By rotating these corrugated splines within elongate tubes that form part of the respective subassemblies, it is possible to remove crystalline, corrosive, and other build-up.

Abstract: A collapsible boat comprising forward and aft hull sections, each of which comprising a plurality of longitudinal frame members and transverse cross members. The frame members are joined into longitudinal alignment by sliding a male end of a frame member into a complimentary female end of an adjacent frame member. The frame members are also interconnected to the cross members at a plurality of connector portions to create the forward and aft hull sections. Interlocking mechanisms are used to join together the forward and aft hull sections to define a hull framework having elongate frame members that extend longitudinally between a bow and stern and that are spaced and braced by transversely extending cross members. A variable tensioning mechanism permits variation of the elevation of the bow and stem of the framework by adjusting the overall length of the elongate frame members.

Abstract: A collapsible boat having a framework comprising forward and aft keel member portions, forward and aft port and starboard gunwale member portions, forward and aft port and starboard stringer member portions, and a plurality of cross-rib members. The keel, gunwale and stringer member portions are joined by interconnecting members into aligned longitudinal members that are also interconnected to the cross-rib members to create forward and aft hull sections. A keel locking and tensioning mechanism is used to join together the forward and aft hull sections at the keel to define a hull framework having elongate keel, gunwale and stringer members that extend longitudinally between a bow and stern and that are spaced and braced by transversely extending cross-rib members. A rocker adjustment system in the gunwale member portions joins the forward and aft gunwale members and permits variation of the elevation of the bow and stern of the framework by adjusting the overall length of the gunwale member portions.