Since 1964, the Westlake Street production facility behind Fins Unlimited has manufactured surfboard fins in Encinitas, making it one of the longest-operating fin companies in the United States. The product line spans single-fin longboard templates, twin-keel sets, thruster clusters, and quad-tow configurations sold through surf retailers including Bing Surfboards on South Coast Highway 101. Every fin is built from woven G-10 fiberglass laminate and profiled to NACA foil specifications developed by the National Advisory Committee for Aeronautics, producing thinner cross-sections that reduce drag and increase responsiveness compared to injection-molded alternatives. Production runs at the Westlake Street facility use hand-laid fiberglass cloth with resin infusion at controlled temperatures, and surfers who field-test prototypes in the heavy winter swells off Leucadia recover afterward at spots like Beach Sauna nearby. The highest-performance models in the line — the G-10 Quad Tow set at 3.75 inches — use aerospace-grade fiberglass layups rated for the speed and hold required in overhead-plus tow-in conditions.