Sail construction comprising foldable sail supports (2), a crossbeam (3), a holder (1.1), a sail (1), a bottom holder (4), ropes (4.3) and a bolt and tackle system. The sail can be a self-inflatable sail (1 SN) designed similarly to paragliders, partially or fully inflatable.

A command and control bar for a kite sail associated with two front cables connected to a user and two rear cables connected to the bar. The cables are connected at one end to the sail. An adjustment element to shorten/extend the rear cables is incorporated into the bar and can be controlled by the user without releasing the bar. A deflection system can be displaced parallel to the axis of the bar and is connected to a return element. The bar includes a locking element to lock/release the position of the deflection system along the bar, depending on the traction forces applied on the cables. The locking element is accessible to the user from outside the bar.

A command and control bar for a kite sail associated with two front cables connected to a user and two rear cables connected to the bar. The cables are connected at one end to the sail. An adjustment element to shorten/extend the rear cables is incorporated into the bar and can be controlled by the user without releasing the bar. A deflection system can be displaced parallel to the axis of the bar and is connected to a return element. The bar includes a locking element to lock/release the position of the deflection system along the bar, depending on the traction forces applied on the cables. The locking element is accessible to the user from outside the bar.

A safety release mechanism for kite surfing with a safety release member by which a kite surfer is attached to the body. A locking element detachably secures an attachment end of the safety release member to the body. A resilient element urges the locking element into the unlocked position, such that upon release for the locking element, the resilient element moves the locking element to the unlocked position thereby resulting in a release of the attachment end of the safety release member, regardless of the orientation of the device, the orientation of the kite, or the available strength of the kite surfer.

A deck coupled to a paddle board having a base having a longitudinal axis, an axial axis substantially perpendicular to the longitudinal axis. A base length that is substantially in line with longitudinal axis, a paddle board width that is substantially in line with the axial axis. A bow side having a hull for displacing the water, a stern side, a port side, and a starboard side. A first rung integrally coupled to the port side, the first rung having a first rung bow side, a first rung stern side, and a first rung base positioned between the first rung bow side and the first rung stern side. A second rung integrally coupled to the starboard side, the second rung having a second rung bow side, a second rung stern side, and a second rung base positioned between the second rung bow side and the second rung stern side.

Various embodiments of a submerged sailing vessel are disclosed. Such a submerged sailing vessel may comprise a submersible hull assembly, a keel coupled to and extending upwards from hull assembly towards a water surface, and a wind-catching assembly coupled to and extending upwards into the air from the keel for propelling the submerged sailing vessel. The hull assembly and keel are submerged below the water surface as the vessel is propelled by the wind-catching assembly above the water surface.

A Flettner rotor that employs localized suction over its surface improves performance and fuel efficiency. Simulations and analysis show that such a method can significantly improve the performance of the Flettner rotor. Improvements in rotor performance enable reduction in fuel costs and greenhouse gas emission by ships or other modes of transport. Improvements in rotor performance can also reduce noise for applications such as drones or other devices having rotors.

A Flettner rotor that employs localized suction over its surface improves performance and fuel efficiency. Simulations and analysis show that such a method can significantly improve the performance of the Flettner rotor. Improvements in rotor performance enable reduction in fuel costs and greenhouse gas emission by ships or other modes of transport. Improvements in rotor performance can also reduce noise for applications such as drones or other devices having rotors.

A command and control bar for a kite sail associated with two front cables connected to a user and two rear cables connected to the bar. The cables are connected at one end to the sail. An adjustment element to shorten/extend the rear cables is incorporated into the bar and can be controlled by the user without releasing the bar. A deflection system can be displaced parallel to the axis of the bar and is connected to a return element. The bar includes a locking element to lock/release the position of the deflection system along the bar, depending on the traction forces applied on the cables. The locking element is accessible to the user from outside the bar.

A command and control bar for a kite sail associated with two front cables connected to a user and two rear cables connected to the bar. The cables are connected at one end to the sail. An adjustment element to shorten/extend the rear cables is incorporated into the bar and can be controlled by the user without releasing the bar. A deflection system can be displaced parallel to the axis of the bar and is connected to a return element. The bar includes a locking element to lock/release the position of the deflection system along the bar, depending on the traction forces applied on the cables. The locking element is accessible to the user from outside the bar.