Techniques are provided for an unmanned surface vehicle including a vehicle body and a rigid square-rig wing coupled with the primary vehicle body. The rigid square-rig wing includes a first surface configured to interact with wind to generate a force that propels the primary vehicle body in a direction of travel that is primarily composed of drag, and a second surface configured to interact with the wind to generate a force that propels the primary vehicle body in a direction of travel that is primarily composed of lift. The unmanned surface vehicle further includes a rudder and a control system comprising a controller, the control system configured to determine a rudder position and generate a signal to position the rudder to the rudder position.

Techniques are provided for an unmanned surface vehicle including a vehicle body and a rigid square-rig wing coupled with the primary vehicle body. The rigid square-rig wing includes a first surface configured to interact with wind to generate a force that propels the primary vehicle body in a direction of travel that is primarily composed of drag, and a second surface configured to interact with the wind to generate a force that propels the primary vehicle body in a direction of travel that is primarily composed of lift. The unmanned surface vehicle further includes a rudder and a control system comprising a controller, the control system configured to determine a rudder position and generate a signal to position the rudder to the rudder position.

A kite leading edge has a tubular structure having a first curve in a span-wise direction and a second curve a chord-wise direction. The tubular structure is formed by a plurality of panels joined together at seams including at least a first longitudinal seam running in the span-wise direction of the tubular structure. At least a portion of the first longitudinal seam defines a first partial helical path about the circumference of the tubular structure.

Techniques are provided for an unmanned surface vehicle including a vehicle body and a rigid square-rig wing coupled with the primary vehicle body. The rigid square-rig wing includes a first surface configured to interact with wind to generate a force that propels the primary vehicle body in a direction of travel that is primarily composed of drag, and a second surface configured to interact with the wind to generate a force that propels the primary vehicle body in a direction of travel that is primarily composed of lift. The unmanned surface vehicle further includes a rudder and a control system comprising a controller, the control system configured to determine a rudder position and generate a signal to position the rudder to the rudder position.

Woven UHMWPE fabric stretches in the bias direction to such an extent that it is unsuitable for many potential applications and is porous, allowing air and water transmission. A composite UHMWPE material includes a single ply of high tenacity woven UHMWPE fabric having warp fibers in a first direction and weft fibers in a second direction orthogonal to the first direction. The UHMWPE fabric has first face and a second face. A stretch resisting axially oriented fusion layer is fused to at least one of the first face or the second face of the UHMWPE fabric with an axis aligned parallel to at least one of the UHMWPE fabric warp and weft axes, such that the stretch resisting fusion layer increases fabric tensile strength and inhibits bias stretch of the UHMWPE fabric, and renders the UHMWPE woven fabric air and water impermeable.

Woven UHMWPE fabric stretches in the bias direction to such an extent that it is unsuitable for many potential applications and is porous, allowing air and water transmission. A composite UHMWPE material includes a single ply of high tenacity woven UHMWPE fabric having warp fibers in a first direction and weft fibers in a second direction orthogonal to the first direction. The UHMWPE fabric has first face and a second face. A stretch resisting axially oriented fusion layer is fused to at least one of the first face or the second face of the UHMWPE fabric with an axis aligned parallel to at least one of the UHMWPE fabric warp and weft axes, such that the stretch resisting fusion layer increases fabric tensile strength and inhibits bias stretch of the UHMWPE fabric, and renders the UHMWPE woven fabric air and water impermeable.

A fabric for a ship traction structure, formed from multifilament continuous warp yarns and weft yarns and coated on one or both of its two surfaces with a polyurethane (PU), the bare fabric having a coverage rate TC of between 1.8 and 4, the yarns being made of poly(ethylene terephthalate) (PET), the fabric having a density of between 20 and 50 yarns/cm, in terms of warp and weft density, the polyurethane being a crosslinked PU that is polyether-, polyester-, or polycarbonate-based, and this PU being derived from the crosslinking (1) of a single-component polyurethane having a modulus at 100% elongation less than or equal to 5 MPa, in particular between 1 and 4 MPa, in particular between 1 and 3 MPa, according to the standard DIN 53504, implemented in organic solvent phase; (2) by a crosslinking agent, based on a proportion of dry crosslinking agent relative to the dry elastomer of between approximately 5% and approximately 30% by weight, the fabric having a weight, coating included, ranging from 43 or 44 to 250 g/m.sup.2. A ship traction structure, in particular of the paraglider sail type, made with such a fabric.

A training device having a platform for receiving at least one person; at least one anchoring point for fastening a securing means that secures the person on the training device; a vertical rotation axis Z, about which the training device can be mounted rotatably or is mounted rotatably. The anchoring point is arranged at or above the height of the buttocks region of the person, and the training device is rotatable about this rotary axis Z by means of forces acting on the platform.

A method for monitoring air pressure in a kite when kite boarding is described. The method involves a first step of connecting an air pressure sensor to one or more bladders of the kite. The method involves a second step of positioning a visual display for the air pressure sensor where it will be visible to a user conducting a visual inspection of the kite to display a pressure reading as sensed by the pressure sensor.

Disclosed is a hand held wing rig a center strut of which has recessed grips.