Abstract: A cleat for mooring a watercraft at a thrown end of a line has a base surmounted by a body, the base being fastenable to a watercraft deck, the line having a rope and stopper formed by a transverse protuberance, the cleat having an engagement part adjoining the base and a funnel-shaped through-opening to an elongate slot in the body, the slot having a height allowing the longitudinal progression and transverse passage of the rope from the opening towards the interior of the body, the slot leading into a chamber having a minimum dimension greater than the minimum slot height, the maximum dimension of the chamber being less than the dimension of the protuberance forming the stopper so the stopper of a line passing transversely through the body can be blocked against a the body side face both with the rope in the slot and in the chamber.