Abstract: A rigid hull boat made up of detachable bow and stern sections. These are joined at abutting transverse bulkheads: male locking lugs project from the bulkhead of the bow section, and these are received in corresponding recesses in the bulkhead of the stern section. The upper edges of the bulkheads are held together by a channel member through which bolts are passed. The interlocking elements eliminate side-to-side movement between the two bulkheads, and also prevent them from spreading apart at the bottom. There are also bevels around the edges of the two sections which guide the locking members into engagement. The bow section nests within the stern section for storage. If desired, the two sections can be used as independent craft, and in some embodiments, the bow section may be inverted and mounted atop the stern section to provide an enclosed cartop carrier.