Provided is a radar and communications enhanced sail for a sailboat, sail ship, or sail drone. The sail includes a first sail section comprising an active communication system, a second sail section comprising a passive communication system, or a combination thereof. The active communication system includes an antenna array (transceiver) and a software-defined radio (SDR), while the passive communication system comprises a reflective panel or sections and/or array of reflector panels or sections. The active system utilizes its SDR and transceiver to communicate back and forth with an onshore SDR and transceiver to provide information as necessary. The passive system receives a radar signal via the reflective material on the sail and reflects the signal back at the radar, which produces a radar cross section indicating that there is an object (in this case the sailboat) in the ocean.

Provided is a radar and communications enhanced sail for a sailboat, sail ship, or sail drone. The sail includes a first sail section comprising an active communication system, a second sail section comprising a passive communication system, or a combination thereof. The active communication system includes an antenna array (transceiver) and a software-defined radio (SDR), while the passive communication system comprises a reflective panel or sections and/or array of reflector panels or sections. The active system utilizes its SDR and transceiver to communicate back and forth with an onshore SDR and transceiver to provide information as necessary. The passive system receives a radar signal via the reflective material on the sail and reflects the signal back at the radar, which produces a radar cross section indicating that there is an object (in this case the sailboat) in the ocean.

In order to provide a rigid sail or aerofoil sail which has a lower overall weight, is cost-effective to manufacture and does not affect the passing under bridges, power lines or similar structures arranged over busy waters, in the case of a rigid sail for vessels, in particular, for large ships, such as bulk carriers, tankers, car transporters or bulkers, comprising a mast and a first aerofoil wing body mounted on the mast with a base and a head, wherein the mast is inserted through the base into the first aerofoil wing body and is arranged within the first aerofoil wing body, it is proposed that the mast, starting from the base, does not extend beyond a maximum height of the first aerofoil wing body, in particular, less than 75% of the maximum height.

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.

Propulsion apparatus for an aquatic vessel comprises an aerodynamic body which extends along a longitudinal axis between first and second ends and in a transverse direction between a leading edge and trailing edge. The aerodynamic body has one or more external wind-receiving surfaces which extend between the leading edge and the trailing edge, thereby defining an aerodynamic profile of the aerodynamic body in cross-section substantially perpendicular to the longitudinal axis. The propulsion apparatus further comprises at least one air vent and at least one air flow generator configured to expel air through the at least one air vent. The at least one air vent and/or the at least one air flow generator are configured to direct expelled air across at least a portion of the one or more or more external wind-receiving surfaces.

Propulsion apparatus for an aquatic vessel comprises an aerodynamic body which extends along a longitudinal axis between first and second ends and in a transverse direction between a leading edge and trailing edge. The aerodynamic body has one or more external wind-receiving surfaces which extend between the leading edge and the trailing edge, thereby defining an aerodynamic profile of the aerodynamic body in cross-section substantially perpendicular to the longitudinal axis. The propulsion apparatus further comprises at least one air vent and at least one air flow generator configured to expel air through the at least one air vent. The at least one air vent and/or the at least one air flow generator are configured to direct expelled air across at least a portion of the one or more or more external wind-receiving surfaces.

A process of printing an image or images on the sails of a watercraft or other wind powered objects without altering or compromising the efficacy of the sails is described. The process employs a method of printing large-scale, single or multiple panel, continuous, high-resolution photographic and graphic images on wind-catching fabrics. The dynamics and curvatures of a sail are integrated into the manufacturing process when employed for sails, though the process may be applied to any large-scaled fabric print. The process of the present invention produces printed sails providing for the highest resolution photographic, art, and graphic printing with virtually no weight gain, nor effect on the sail's original performance. Modern equipment is employed to achieve printing of realistic, high quality images directly on to the fabric of sails without compromising flexibility or durability, as well as without infringing on the speed and agility of the sailing craft.

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 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.

The present disclosure is directed generally toward sailing vessels. One example is a catamaran with one or more pivoting masts per hull member, which may pivot from a generally perpendicular upright position, to a generally flat stowed position toward the bow of the hulls. The masts are capable of sustaining a plurality of sails, which may travel 180 degrees with respect to the hulls.