The present invention relates to a fairlead (1) for guiding an anchoring chain (C) and intended is to be provided to anchoring equipment (2) on the floor of a floating platform. Said fairlead (1) comprises a direction-reversing structure (10), for guiding a change in direction of said corresponding anchoring chain (C), and a locking structure (11) that comprises a jaw assembly consisting of two jaws that are combined with a means (22) for rotatably moving said jaws in a reverse direction. Said moving means (22) comprises: (a) a so-called "counterweight" inert mass (25) that is movably coupled with said jaws and that is height-adjustable between a low position and a corresponding high position, to an operative position and an inoperative position of said jaws, respectively, so as to move and tend toward maintaining said jaws in said operative position; and (b) an actuating means (26) that is controlled by a control means, and is intended for moving said jaws from said operative position to said inoperative position, and is intended for moving said counterweight (25) from said low position to said high position.