A flat bottom boat including an upper hull portion and a lower hull portion. The upper hull portion has a first width and a lower surface. The lower hull portion has a second width that is less than a first width. The lower hull portion extends from a lower edge of the upper hull portion. A lower surface of the lower hull portion is substantially flat.

A collapsible kayak may include a single-piece hull including a plurality of crease lines along which the hull is foldable. A floorboard lines a midship portion of the hull between a bow portion and a stern portion, and the floorboard includes a base and a pair of outboard walls permanently fixed at distal ends to port and starboard gunwales of the hull. The bow, stem, and midship portions are configured as a tri-fold, such that the bow portion and the stern portion of the kayak are foldable toward each other to overlap the midship portion of the hull when collapsed.

An inflatable hull including at least one air casing that has two walls placed one over the other. The walls each include a fabric sheet, are connected therebetween by a plurality of connecting wires distributed over the entire surface of the sheets while forming a structure suitable for being inflated to a pressure capable of rigidifying the structure, and are capable of ensuring the buoyancy of the hull separately from any reported buoyancy element. The casing has a first transversely cross-sectional curvature and a second longitudinally cross-sectional curvature that is present over at least the front portion of the casing. One of the walls corresponds to the inside of the curvature, and the other of the walls corresponds to the outside of the curvature. The casing has at least one clip set up such as to form a stem.

A collapsible kayak may include a single-piece hull including a plurality of crease lines along which the hull is foldable. A floorboard lines a midship portion of the hull between a bow portion and a stern portion, and the floorboard includes a base and a pair of outboard walls permanently fixed at distal ends to port and starboard gunwales of the hull. The bow, stern, and midship portions are configured as a tri-fold, such that the bow portion and the stern portion of the kayak are foldable toward each other to overlap the midship portion of the hull when collapsed.