To provide a fin for a marine rudder which is reduced in weight and has a sufficient stability against a steering force acting on the fin.

To improve the characteristics of a fin 40 for a marine rudder of fin type, the fin 40 is made of a fiber composite material. For the production of a fin body, it is desirable to integrate two half shells and reinforcing elements, which, depending on circumstances, are disposed between the half shells, with each other in the fin body. In the production method, for the production of the fin body, the fiber composite material is wrapped and/or laminated around one or more cores, particularly, foam cores, and/or one or more receiving joint elements.