Abstract: A strap with tapered-apertures for open-heeled swim fins is stretched from a first end connection to a conventional boss-button and boss-post structure, whereby the strap will apply a desired level of force as a holding-pressure against the heel of a swimmer. The strap's tapered-apertures are cast to link the tapered dimensions of aperture walls to an easy passage of the strap over the boss button and to a highly resistant passage of the strap-top to a designed seat against the top's raised arches. The manufactured formation of the unique aperture shapes result in an unexpected elasticity of the strap. The combination of aperture structure within the raised arches guide the orifice walls of the aperture into compression, instead of tension, greatly resisting forces to release the strap from the boss-posts and buttons.

Abstract: A strap with tapered-apertures for open-heeled swim fins is stretched from a first end connection to a conventional boss-button and boss-post structure, whereby the strap will apply a desired level of force as a holding-pressure against the heel of a swimmer. The strap's tapered-apertures are cast to link the tapered dimensions of aperture walls to an easy passage of the strap over the boss button and to a highly resistant passage of the strap-top to a designed seat against the top's raised arches. The manufactured formation of the unique aperture shapes result in an unexpected elasticity of the strap. The combination of aperture structure within the raised arches guide the orifice walls of the aperture into compression, instead of tension, greatly resisting forces to release the strap from the boss-posts and buttons.

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: Hand fins for swimmers include an aerodynamic cross-section that is shaped to generate hydrodynamic lift when water passes over it. Water flowing over a main body portion is guided toward a center of the hand fin to maximize performance. A handle portion is provided preferably via an opening in the main body portion. A wrist strap is attachable to the handle portion to help support a user's hand during use, thereby enhancing the power and control of the hand fin. The hand fin may be constructed of multiple materials with a rigid internal structure and a flexible outer surface, as an inflatable hand fin, and as hollow hand fin having an internal chamber. Some embodiments of the hand fin is designed to flex under water pressure during use, to produce larger lifting surfaces thus producing greater lift.