Split Fin Patent Pedigree
In 1984, Master Fin Designer Bob Evans filed his original Force Fin patents. Included in the specifications was variation in the ratio of the length of wing tips to the overall length of the fin blade. In 1990, Force Fin's Master Fin Designer Bob Evans was issued patent number 5,356,323 for a fin with a split extending more than 25% of its overall length. In 1999, he was issued a design patent on the Foil Force split fin blade.