Abstract: A RIB, rigid-hull inflatable boat (22) includes an inflatable tube (24) having a general U-shape with a forward end (26) at the bight of the U and trailing sides (28 and 30) extending rearwardly therefrom along the legs of the U. A unitary rotationally molded hull (32) is nested within the tube and has right and left sides (34 and 36) extending along inner surfaces of the tube, and a transom extending between the right and left sides. The hull is detachably secured to the underside of the tube by a mechanical locking device (132) permitting simple detachment and reattachment of the tube to the hull. A recessed channel (188) is provided in a concave surface of the hull engaging the tube and extending around the perimeter of the hull and forming a gutter for draining water aft from the interface between the hull and the tube.