A traction system, notably for a ship, includes a fixed station, at least one first sail and one second sail, the first sail comprising a wing and being connected to a winch of the fixed station by a first hauling cable, the second sail includes a second wing and being connected to a winch of the fixed station by a second hauling cable. The fixed station includes a mast which is equipped with a first conveyor dedicated to mooring the first wing to this mast and with a second conveyor dedicated to mooring the second wing to this mast.

A traction system for a watercraft, including a sail and a fixed station that includes a mast and a winch which is connected to the sail by a traction cable, the system further including a bottom part that is supported by the traction cable, and fold lines, each of which has an end that is attached to a leading edge of the sail, and another end that is supported by the bottom part. The fixed station includes a base that accommodates the bottom element when the sail is retracted by the winch; and structure for grasping each fold line and pulling same towards the mast so as to retract the leading edge against the mast and fold the sail once the winch has retracted same close to the station.

A kayak sail system includes a sail including a first extending arm, a second extending arm, and a sail sheet supported between the first extending arm and the second extending arm. A deployment body for the sail includes a base plate supporting a first deployment arm and a second deployment arm. The first deployment arm is coupled to the first extending arm of the sail. The second deployment arm is coupled to the second extending arm of the sail. A support arm is spaced apart from the base plate. A first support post and a second support post extend from the support arm. A first extension spring extends from the first deployment arm and a second extension spring extends from the second deployment arm. The first extension spring is removably coupled to the first support post. The second extension spring is removably coupled to the second support post.

An aerofoil sail (30) for providing motive power to a waterborne vessel, the sail comprising a leading aerofoil portion (35a) and a trailing aerofoil portion (35b), and the sail comprising a spar (32), at least one of the aerofoil portions rotatably positionable, and the sail comprising a controller to control individually the angular position of at least one of the aerofoil portions relative to the spar, and the spar rotationally positionable about its longitudinal axis.

A propulsion system for a boat comprises a plurality of aerofoils connected to a main mast. At least one of the aerofoils is a displaceable aerofoil adapted to be displaced along the main mast between an open position and a closed position. When the displaceable aerofoil is in its open position the aerofoils together form a sail of open sail area. When the displaceable aerofoil is in its closed position at least some of the aerofoils overlap to form a sail of closed sail area, the closed sail area being less than the open sail area. The propulsion system can include a displacement mechanism to displace the displaceable aerofoil between its open and closed positions; at least one of the aerofoils having a solar panel thereon; and/or a stub mast extending along and free to rotate about a stub axis and; connected to the main mast by a stub pivot.

A sailing boat includes at least one mast with at least one first and one second section projecting upwards with respect to the hull and arranged facing each other in the orthogonal direction to the advancement direction for supporting a mainsail in two mutually specular and alternative operating positions, where the sections are connected and spaced out from each other by at least one overturning section of the mainsail placed at the top of them to allow the passage from one specular position to the other. The three sections of mast define for that purpose a first sliding guide for the whole mainsail that extends substantially along the whole extension length of the mast and the mast includes a second sliding guide positioned substantially at the top thereof and placed aft with respect to the overturning section.

Sail construction comprising foldable sail supports, a crossbeam, a holder, a sail, a bottom holder, ropes and a block and tackle system. The sail can be a self-inflatable sail designed similarly to paragliders, partially or fully inflatable.

One embodiment of a mast-head standing rigging connection device, allowing for sail module rotation about a mast axis, is disclosed. The embodiment allows for connection of shrouds and conventional single mast forestay and backstay rigging systems. Additional embodiments, utilizing modifications of the first embodiment, for multi-mast and triangular fore-aft sail mast roller reef-furl systems, are described.

A kayak sail system includes a sail including a first extending arm, a second extending arm, and a sail sheet supported between the first extending arm and the second extending arm. A deployment body for the sail includes a base plate supporting a first deployment arm and a second deployment arm. The first deployment arm is coupled to the first extending arm of the sail. The second deployment arm is coupled to the second extending arm of the sail. A support arm is spaced apart from the base plate. A first support post and a second support post extend from the support arm. A first extension spring extends from the first deployment arm and a second extension spring extends from the second deployment arm. The first extension spring is removably coupled to the first support post. The second extension spring is removably coupled to the second support post.

A watercraft incorporating a wind propulsion system, revealing a main mast and an auxiliary mast. According to the invention, provision is made for a length of the auxiliary mast between a flexible joint and the deck as well as an included angle from the main mast and deck capable of being locked in position on variable lines.