Structural units and associated components and members which make up the fuselage, cockpit, hull and keel, ballast provision, water rudder and water rudder guard, Seawings™, center wing section, IPS riser attachment(s), engine cowl and vertical tail including the air rudder and its hinges and counterbalance. Includes: skins, bulkheads, ribs, fuselage-to-wing fillets, door/canopy jambs, as well as integral or mounted aircraft hand-holds, tie downs and mooring cleats, mid, forward, and aft wing pin receptacles, and firewall structure with thermal protection material(s) as required.