Optimized Pivoting Blade During the finning stroke, the structure of traditional fins tend to limit the flexing angle of the blade. Consequently, especially in the downward movement, only a small part of the fin pushes the water in the direction of motion, while the remaining part pushes the water in the opposite direction, reducing the diver"s forward thrust. The O.P.B. system; patented by Mares, allows the blade to assume an optimal angle during both the upward and downward strokes, thus considerably increasing efficiency. All the divers muscular efforts translate into thrust in the direction of motion. Another limitation of traditional fins is the degradation of the thrust produced during the finning stroke, with substantial differences between the maximum and minimum values. The O.P.B. system, on the other hand, ensures optimal thrust throughout every phase of the finning stroke, thereby minimizing fatigue and affording much more fluid movement through the water. Channel trust Technology When water spills over the blade sides, it does not contribute to thrust, and simply decreases efficiency. If appropriate channeling occurs, all the displaced water adds thrust. The "Channel Thrust" technology makes it possible to maximize channeling of the fluid streams and to move a much greater amount of water compared to other fins of the same size. The resulting advantage is greater thrusting power with the same amount of effort.