Abstract: A surfboard with a fin is developed to counteract the tendency for skegs or fins to "pop out" especially when the surfer "walks the nose" of the surfboard or rides high on a wave. The fin has a pair of opposed wing hydrofoils extending laterally from an approximately mid-point position on a vertical hydrofoil having a forwardly arcuate relieved portion above the wing hydrofoils, a downwardly-rearwardly swept leading edge and a rearwardly-upwardly swept trailing edge terminating at the confluence of the rear edges of the wing hydrofoils.