Representing the Authority invested with the exercise of Port Policing Powers, the Harbour master is tasked with coordination which is enforced in compliance with port safety and security rules. It is in charge of the policing of road and rail networks and waterways - conservation of public domain and its exploitation, i.e. protection of the environment and safety of installations. It is also in charge of navigation policing, beacons and lighting systems, railway networks, dangerous substances and enclosed premises.

This police force is dedicated to the port and exercises the power to issue summary orders and thereafter to act, drawing up offence notices and sanctioning them with penalty notices.

It issues authorisations to carry out repair work on vessels, is in charge of crisis management, the coordination of fire fighting and port contamination containment, as well as the reception of ships in distress. It is also consultant on port facilities and design of installations.
Further details on DML: Délégation à la Mer et au Littoral Seine-Maritime & Eure
http://www.seine-maritime.gouv.fr/Politiques-publiques/Mer-littoral-et-peche