The shoe is made of elastic rubber or thermoplastic. A swimming fin (6) is formed directly out of the top shoe instep (5) as an upward extension and is curved in a lengthwise direction, and swings over the ankle joint (Fg). The primary cross-section of the fin is semi-elliptical. The middle part of the fin on the inside (I) has a raised ridge (9). The outside of the fin near the free end has a raised ridge (8) with two straight side shapes (8a) at a tangent to the half-ellipse. The tread sole (3) has a horizontally protruding point (7).
