Fin assemblies for a variety of watersport boards including wakeboards, sailboards, surfboards and the like. The fin assemblies include a fin cap, at least one fin base and at least one locking member. Fin assemblies are secured to a watersport board by passing at least one locking member through channels in the board and fin base and into sockets in the fin cap. Fin assemblies are reconfigured by first removing the locking members, arranging the desired combination of fin cap and fin base suitable for current water conditions and/or user ability and then resecuring the fin assembly to the board with locking members.