Voit V Duck Surf Fins This legendary fin is now constructed and shaped for maximum surf performance from dual density rubber with a soft rubber foot pocket and a stiff blade. Non-marking and full-floating, this fin is hydro-dynamically designed for greater propulsion with minimal effort. Sizing: XXS 1-3, XS 3-5, S 5-7, M 7-8, L 8-9, XL 9-11, XXL 11-13