The term gaff rig designates any sail with four sides, generally trapezoidal, located in the axis of a sailboat. It is known for always receiving the wind through the same leading-edge, the luff or front leech. The horn sails of the Don du Vent, a prestigious auric ketch moored at the Vieux-Port (Old Port) of Marseille, are part of the gaff sails category. Their fore rope is attached to a mast, and the sails are held down by a boom.