A fin for a water sports board including leading and trailing edges, and a base extending therebetween along a longitudinal base axis. A fin axis extends generally perpendicular to the longitudinal base axis, both axes residing within a longitudinal plane. First and second opposed side faces are formed on generally opposed sides of the longitudinal plane. First and second insert pre-preg sheets formed of structural strands bonded by a resin material are disposed adjacent respective ones of the first and second side faces on generally opposed sides of the longitudinal plane. An injection molded resin material is disposed between the first and second insert pre-preg sheets. A core is positioned between the first and second insert pre-preg sheets and is of a density less than the injection molded resin material.