The incident

In the early hours of 3 December 2016, the bulk carrier Muros ran aground on Haisborough Sand, 8 miles off the Norfolk coast and the master’s attempts to manoeuvre the vessel clear were unsuccessful due to a falling tide. The vessel was re-floated 6 days later and was towed to Rotterdam for repair. When Muros grounded, the vessel was following a passage plan shown on its electronic chart and display information system (ECDIS). The plan had recently been revised on the ECDIS by the OOW who then used the system to monitor the vessel’s position.


  1. The vessel was following a planned track across Haisborough Sand. The passage plan in the ECDIS had been revised by the second officer less than 3 hours before the grounding and it had not been seen or approved by the master.
  2. A visual check of the track in the ECDIS using a small-scale chart did not identify it to be unsafe, and warnings of the dangers over Haisborough Sand that were automatically generated by the system’s ‘check route’ function were ignored.
  3. The second officer monitored the vessel’s position using the ECDIS but did not take any action when the vessel crossed the 10m safety contour into shallow water.
  4. The effectiveness of the second officer’s performance was impacted upon by the time of day and a very low level of arousal and she might have fallen asleep periodically.
  5. The disablement of the ECDIS alarms removed the system’s barriers that could have alerted the second officer to the danger in time for successful avoiding action to be taken.

Safety Issues

  • The intended track over Haisborough Sand was unsafe and grounding was inevitable given the vessel’s draught and the depth of water available
  • ECDIS safeguards were ignored, overlooked or disabled
  • The track over Haisborough Sand was not planned or checked on an appropriate scale chart
  • The revision of the passage plan conficted with the 2/O’s watchkeeping duties
  • The master directed the OOW to revise the route but he did not see or approve it
  • The OOW’s performance was probably adversely affected by a low state of alertness
  • The use of software to disable the audible alarm and the guard zone removed the ECDIS barriers intended to alert bridge watchkeepers to imminent danger
  • The use of the ‘standard’ chart view limited the information displayed and the reliance of visual checks when passage planning was prone to error
  • ECDIS use on board Muros was not as envisaged by regulators or equipment manufacturers.

Actions taken 

UK MAIB has commenced a safety study, in collaboration with the Danish Maritime Accident Investigation Board, to provide further research on the reasons why seafarers are utilising ECDIS in ways that are often at variance with the instructions and guidance provided by the system manufacturers and regulators.

The overarching objective of the study is to provide comprehensive data that can be used to improve the functionality of future ECDIS systems by encouraging the greater use of operator experience and human centred design principles.

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