Sail-board with triangular stern fin - has lugs at top corners bearing against pivot points in all hull under pressure from return spring

摘要

The sailboard with a stern fin basically has this mounted so that it can pivot about a transverse axis, pref. near the hull undersurface, with a spring to return it to working position. Two such pivot points (5,6) longitudinally displaced, are provided, in the board structure. The fin (3), shaped as an isosceles triangle, has lugs (7,8) or similar projections from its top corners resting on these points so that it can tilt forwards as well as backwards. The spring (4), which bears against the top of the fin, may be an elastic band secured to the board at both ends.