Abstract: A fin with a hydrodynamic flex control framework allows the axis of bending to be in close proximity to the ball of the user's foot making kicking easier as well as more productively efficient and a method providing thrust from an unusually low drag kick by a swimmer are disclosed. The fin includes a fin for use by a swimmer comprising a foot pocket adapted to receive a foot of the swimmer; a foil shaped blade extending from the foot pocket; hydrodynamic flex control framework configured to allow the blade to bend in close proximity to the ball of the user's foot within a narrow range of angles of attack under a wide range of loads while enhancing hydrodynamic performance. The present invention allows low drag kicking by a swimmer that is similar to walking in place with the user's feet staying within the user's slip stream.

Abstract: A fin and a method providing thrust from an unusually low drag kick by a swimmer are disclosed. The fin includes a fin for use by a swimmer comprising a foot pocket adapted to receive a foot of the swimmer; a foil shaped blade extending from the foot pocket; composite hydrodynamic flex control framework configured to allow the blade to bend within a narrow range of angles of attack under a wide range of loads while enhancing hydrodynamic performance. The method comprises providing a fin comprising a foot pocket, a foil shaped blade, an aperture, and two living hinges positioned adjacent to foot pocket. The method also comprises bending the blade relative to the foot pocket about an axis that is nearer the heel of the swimmer to reduce centrifugal forces while controlling the bending of the blade by providing living hinges formed to increase resistance as kicking power increases.

Abstract: MULTIPLE-SERIAL-HYDROFOIL swim fins use aerodynamic shapes to help with propulsion through the water. By producing “lift” as an additional power source for swimming, they provide more power for the swimmer without additional effort from the swimmer. The planar blade helps to provide self-regulating pitch for the hydrodynamic shapes. The overall reduction in the size and cost of the swim fin is a secondary benefit to the reduction in work for the swimmer. By having multiple self-regulating airfoils (hydrofoils when used in water) in a series properly distanced from one another, the accelerated flow of water over the hydrodynamic shapes increases the effectiveness of the trailing hydrodynamic shapes through serial amplification. The geometry of the swim fins work with high performance materials using sophisticated internal properties (compliant geometry) to manage the self-regulating pitch and serial amplification.

Abstract: The ergonomic swim fin apparatus comprises a foot-pocket sized to fit about a user's foot, channeling scoops are positioned on opposite sides of the footpocket, and a flexible blade extends from the foot-pocket to a trailing edge. A “wing shaped” tail fin is secured to the trailing edge of the flexible blade. The channeling scoops are rounded to channel the water displaced by the user's foot over the flexible blade and tail fin. The flexible blade and wing like tail fin channel water while enhancing lift and thrust. At least one securing strap is used to secure the user's foot to the foot-pocket. The tail fin is preferably selectively attachable and removable from the distal end of the flexible blade. The flow of water across the foot is converted by the channeling scoops into a propulsion stroke in both the up and down strokes, while allowing the foot the freedom to flex naturally at the ankle and toe joints.

Abstract: A dolphin-tail style multi-purpose swim fin that connects to a flat swim fin securable to a user's foot is used to generate propulsion in the form of displaced water. When the connected dolphin-tail style swim fin flows through a path of displaced water from the flat swim fin at a proper angle of attack, it produces a lifting force that assists in swimming. The dolphin-tail style swim fin is shaped to enhance the propulsion from the flat swim fin. A swim fin assembly can be integrated with both flat and dolphin-tail style fins as one unit. The dolphin-tail style swim fin is shaped to generate lift as water flows across it and can be used directly by the hand (without a flat fin) or used with a handle that can be attached in lieu of the flat fin.

Abstract: A swim fin that has the streamlined design of an aquatic fish or mammal with the foot pocket and flexible shaft forming a proportional and similar shape to the body of a fish. The fin is a wing-like shape separate but connected to the shaft similar to the caudal fin of a fish. This streamlined design provides an efficient form of propulsion using only power strokes and the principles of lift similar to fish. Also the tips of the stiff caudal fin create vortices to reduce drag. The flexible shaft is made of a material with a physical "memory" so that it springs back to its original manufactured shape after it flexes to produce a secondary "kick" for the swimmer. This overall "fish or whale" shape also allows for the possibility of a modular construction, if desired, where the flexible caudal shaft and stiff caudal fin can be exchanged with ones of alternative size, shape, material and design so that the fin can be adapted to each swimmer's body type, muscle type, swimming style, and aquatic conditions.