A fairlead that is intended to equip a towing device that can be installed on the deck of a ship and includes a winch, a cable passing through the fairlead under the action of the winch, the fairlead comprising: an open-section channel extending in a main direction for guiding the cable, a movable bolt closing a section of the channel, a force sensor that is situated in front of the bolt in one sense of the main direction and is configured to detect an external force, and a trigger configured to open the bolt when a force exerted on the sensor and oriented along the main axis in the sense exceeds a predetermined force, and to close the bolt when this force ceases.