A Martitime Notice has been issued for the Merseyside Coastline are advised to prepare for intermittent loud noises on:- Monday, 16 March 2026, as regional authorities conduct essential maintenance on coastal safety infrastructure.

The scheduled:- 'Fog Signal Test' is part of a coordinated effort to ensure navigational aids are:- "weather ready" for the spring season. While these tests are routine, the sheer volume of the signals designed to be heard miles out at sea often catches locals off guard.

What to Listen For...

Most residents on the coast will recognise the fog horns, but if you have not heard them before, they can be quite strange to hear. Starting as early as:- 9 am GMT, various lighthouses and shore based stations (like navigation buoys) may emit high decibel blasts. Unlike a true emergency or low visibility event, these signals will occur in short bursts and may not correspond with actual weather conditions. The sound signals help identify specific buoys and guide vessels when visual cues are obscured to shipping.

A maritime safety spokesperson explains:- "These tests are vital for the safety of both commercial shipping and recreational vessels. In the event of a real system failure during a heavy fog, the risks to life and the environment are significant. We test now so we aren't guessing later."

This test coincides with a busy month for the Mersey. The Port of Liverpool has also confirmed that environmental surveys for fish and plankton are currently active across the estuary. Mariners are reminded to maintain a vigilant watch as both survey vessels and maintenance crews will be operating in high traffic lanes.

Guidance for Residents along the Merseyside Coastline:-
  • Noise Sensitivity... Pet owners and those sensitive to loud noises should be aware that the signals are significantly louder than standard sirens. It is often described as a sound that is like a very big truck or train horn. It is also like the ship horns you can sometimes hear... 
     
  • No Action Required... Public members do not need to report the sounds to emergency services unless they see a vessel in distress.
     
  • Vessel Safety... Local sailors are encouraged to monitor:- 'VHF Channel 12' for real time updates from:- Mersey VTS (Vessel Traffic Services).
     
  • Note for Mariners... If you are operating a vessel on the day, Trinity House has specified that the test will only proceed if;- 'visibility is good.' If actual fog rolls in, the test will likely be postponed so as not to interfere with real world safety signals.
The testing is expected to conclude by late afternoon.
 

The Team Behind the Test:-
 

  • Trinity House... They own and maintain the:- "Hazard Warning Systems" (the modern term for fog signals). Their engineers will be the ones physically on site at various stations to conduct the upgrades and trials.
     

  • Mersey VTS (Vessel Traffic Services) operates out of the Port of Liverpool; they act as the:- "air traffic controllers" for shipping on the River Mersey. They will monitor the tests via radio (VHF Channel 12) to ensure no ships are confused by the signals.
     

  • Local Port Authorities... If the tests extend to specific areas, such as the:- Wirral or Sefton, Local councils may also be notified to assist with community:- "noise complaints" or inquiries.
     

Did you know?   The primary organisation responsible for this testing is Trinity House, the official authority for lighthouses and maritime navigational aids in England and Wales. Trinity House typically schedules these:- "preliminary works" and character trials in early spring. This allows them to test the equipment's range and reliability before the heavier sea fogs common in late spring and early summer arrive. While Trinity House manages the equipment, they often coordinate with local port authorities to ensure the public and mariners are informed. In the case of the Merseyside coastline, this involves cooperation with Peel Ports (The Mersey Docks and Harbour Company), who manage vessel traffic in the area.