Safety of Navigation

The Port Marine Safety Code (PMSC) 2009 places responsibility on all ports in the United Kingdom to provide a safe environment for vessels and  people who  operate within the port’s jurisdiction.

There are three areas of jurisdiction within the Dee estuary, two of which are the responsibility of the Port and the third resting with the Dee Conservancy:

1)    The Port is the SHA for all the berths and their immediate approach areas.
2)    The Dee Conservancy is the SHA for the remainder of the esturial area.
3)    The Port is also the Competent Authority for Pilotage in the Dee Estuary Pilotage Area which extends from a seaward point off Point of Ayr upstream to the Old Stone Bridge at Chester.

Safety of navigation in the Estuary is managed through a the Jointly Agreed Procedures Agreement between the Port of Mostyn and the Dee Conservancy. 

This agreement forms part of the Safety Management Systems of both the Port and the Dee Conservancy.

Enforcement and Prosecution Policy

These Safety Management systems are based on formal risk assessment procedures to ensure  that all risks within the marine operations are identified and reduced to levels that are tolerable and as low as reasonably practicable and include:

  • Management of navigation of vessels
  • Communication protocol
  • Pilotage
  • Safe anchorage
  • Contingency planning and emergency responses

More information on the Dee Conservancy see Natural Resources Wales – River Dee conservancy


The Port of Mostyn is responsible for safe navigation in the Dee Estuary which includes a requirement for periodic dredging of the harbour area and the navigational channel.

The Port of Mostyn’s dredging and disposal operations are undertaken in compliance with its current Marine Works License issued by the Welsh Government.