Manually propelled water skis support a person skiing on water. The water ski includes a base having a binding on an upper surface and stationary propulsion structures with uniform height on the bottom surface. The propulsion structures include a rearward facing and vertical propulsion surface and a forward facing and sloped surface such that drag is greater when the water ski is moved rearwardly. The propulsion surface may be arcuate, V-shape, U-shaped, or other shaped in a horizontal plane and may also be circularly concave in a vertical plane. Buoyancy structures may be secured to the upper surface of the base forward and rearward of the binding. Water ski poles including elliptically- or cylindrically-shaped floats at the bottom ends may be used to provide a synergistic increase in waterskiing speed. Straps on the base near the binding may be used to secure the water ski poles to the base in order to form an outrigger.

A water ski fin comprising a planar body and a plurality of chevrons. The planar body may have a top end, a convex leading edge, and a trailing edge. The mounting elements on the top end may mount the fin on a tail of a water ski. A bottom may connect the leading edge to the trailing edge. A plurality of chevrons may have alternating crests and troughs positioned in the trailing edge.

A water ski fin comprising a planar body and a plurality of chevrons. The planar body may have a top end, a convex leading edge, and a trailing edge. The mounting elements on the top end may mount the fin on a tail of a water ski. A bottom may connect the leading edge to the trailing edge. A plurality of chevrons may have alternating crests and troughs positioned in the trailing edge.

Manually propelled water skis support a person skiing on water. The water ski includes a base having a binding on an upper surface and stationary propulsion structures with uniform height on the bottom surface. The propulsion structures include a rearward facing and vertical propulsion surface and a forward facing and sloped surface such that drag is greater when the water ski is moved rearwardly. The propulsion surface may be arcuate, V-shape, U-shaped, or other shaped in a horizontal plane and may also be circularly concave in a vertical plane. Buoyancy structures may be secured to the upper surface of the base forward and rearward of the binding. Water ski poles including elliptically- or cylindrically-shaped floats at the bottom ends may be used to provide a synergistic increase in waterskiing speed. Straps on the base near the binding may be used to secure the water ski poles to the base in order to form an outrigger.

An apparatus for automatically adjusting tension on retention member to hold multiple objects together. Examples include using retention apparatus to obtain optimal fit and use of a human wearable item such as article of footwear. Sensors may be used to sense changes in movement of the article of footwear, of the person wearing it, or of a third object such as a vehicle carrying the person. A retention member may surround at least a portion of the objects, and an actuator may be included that automatically rotates a rotating member such as a gear or pulley that may be coupled to the retention member. The rotating member may be configured to automatically adjust tension on the retention member many times per second based on control signals from control logic responsive to the sensors.

A wearable water shoe apparatus for walking, standing and jet siding on water, includes in each of a first water shoe and a second water shoe (i) a sleeve to receive a leg of a user and (ii) a bottom section, The sleeve has a platform for standing thereon. Each pair of a plurality of pairs of jet motors is configured to eject a jet stream of water. A stabilization unit, including a tilt sensor and a plurality of gyroscopes, is configured to detect a stabilization state of at least one of the first water shoe and second water shoe. A processing unit is configured to receive output from the stabilization unit, determine a direction of movement indicated by the user and direct at least one of the pairs of motors to eject a water stream out of at least one of the water shoes based on the indicated direction.

A wearable water shoe apparatus for walking, standing and jet siding on water, includes in each of a first water shoe and a second water shoe (i) a sleeve to receive a leg of a user and (ii) a bottom section, The sleeve has a platform for standing thereon. Each pair of a plurality of pairs of jet motors is configured to eject a jet stream of water. A stabilization unit, including a tilt sensor and a plurality of gyroscopes, is configured to detect a stabilization state of at least one of the first water shoe and second water shoe. A processing unit is configured to receive output from the stabilization unit, determine a direction of movement indicated by the user and direct at least one of the pairs of motors to eject a water stream out of at least one of the water shoes based on the indicated direction.

The invention relates to water ski (1) having a buoyant ski body (2), to which, in addition to a binding (3), a propelling drive is assigned, which comprises a rotary drive unit with a rotary drive (4) and a screw drive which can be driven thereby, and having a control device (6) for presetting a drive power. In order to create advantageous drive conditions, it is proposed that the water skis (1) of a pair of water skis each comprise a rotary drive unit with at least one drive sensor (7) each, an associated energy storage device and a communication device, which adjusts the rotary drives (4) of both water skis (1) as a function of drive sensor data and preset data of the control device (6).

A water ski fin comprising a planar body and a plurality of chevrons. The planar body may have a top end, a convex leading edge, and a trailing edge. The mounting elements on the top end may mount the fin on a tail of a water ski. A bottom may connect the leading edge to the trailing edge. A plurality of chevrons may have alternating crests and troughs positioned in the trailing edge.

A water ski fin comprising a planar body and a plurality of chevrons. The planar body may have a top end, a convex leading edge, and a trailing edge. The mounting elements on the top end may mount the fin on a tail of a water ski. A bottom may connect the leading edge to the trailing edge. A plurality of chevrons may have alternating crests and troughs positioned in the trailing edge.