Abstract: A fin drive for a watercraft (1) has a lever arm (7, 7') operable with muscle force, which lever arm is connected to an up and down movable carrier (2) through a joint, on which the fin (25) is fastened. The fin (25) is fastened on the carrier (2) on a swivel axis (37) extending transversely in a travelling direction. A rod (26, 27), which can be moved up and down against the force of springs (69 to 72) relative to the carrier (2), is arranged on the front side and the backside of the carrier (2). The fin (25) is pivotally arranged about an axis (36, 38) parallel to the carrier swivel axis (37) on each rod (26, 27). The stroke of the rods (26, 27) can be adjusted relative to the carrier (2).