Mares Plana Avanti X3 Dive FinThe perfect combination of comfort and power for recreational divers and snorkelers. The mid sized blade has three channels for optimal movement of water during the kicking cycle. Ideal for travel and available in XS providing the perfect fin for both women and young divers too. Mares Plana Avanti X3 Open Heel Dive Fins Channel Thrust Technology When water spills over the sides of the blade, it reduces thrust, and decreases efficiency. Mares design