A folding rigid-inflatable boat for routine and emergency use by occupants as an auxiliary watercraft. The floating rigid-inflatable boat includes a hull having complementary rigid bow and rigid stern sections joined together along common, centrally disposed joint edges, a hinge element extending laterally from port to starboard along the centrally disposed joint edges and pivotally connecting the bow and stern sections together for permitting the bow and stern sections to be folded onto themselves into a storage configuration and into an unfolded use configuration; and inflatable topsides secured to the hull and extending around the periphery of the hull for providing an upwardly extending freeboard and for further providing rigidity to the hull when the boat is in the unfolded use configuration.