Patent ID: 8251764

Claim:
A swim fin, comprising a foot cover, a fin blade, and a pair of reinforcement ribs extending from two sides of the foot cover, wherein the fin blade being disposed between the pair of the reinforcement ribs and fixedly connected to the pair of the reinforcement ribs, and characterized by: each reinforcement rib comprising a front rib portion, a middle rib portion, and a rear rib portion, the rear rib portion having a bottom fixedly connected to the foot cover, the middle rib portion having at least a cavity extending axially and a spring in the cavity to improve the resilience of the reinforcement rib, the spring having two ends connected to the front rib portion and the rear rib portion, respectively, a limit rope, without slack in the rope, is provided in the spring, the limit rope having two ends fixedly connected to the two ends of the spring, the middle rib portion including at least a cavity extending axially and a plurality of through holes interconnecting with the cavity, the two ends of the spring are provided with two rings, and the two rings being connected to the front rib portion and the rear rib portion, respectively.