WATCHOUT Erroneous ECDIS chart settings lead to grounding

01 Jun 2020 The Navigator

In this series, we take a look at maritime accident reports and the lessons that can be learned

What happened?

A chemical tanker ran aground on a marked and charted sandbank in the early hours of the morning. The OOW was following a passage plan that had already been programmed into the ECDIS by another officer who was not fully familiar with the system. This plan was not checked prior to departure by the Master or by the OOW before he started his watch.

The OOW on duty was monitoring the tanker’s position solely against the intended route on the ECDIS, which was displaying an inappropriate chart scale for the location. This gave an inaccurate view of the vessel’s intended passage, and did not indicate the shallow water close to the sandbank. Furthermore, the audible alarm on the ECDIS was not working, so neither the OOW nor the deck cadet acting as lookout were warned in enough time to avoid the ship grounding.

It took the OOW a full 19 minutes to realise what had happened. The vessel sustained superficial damage and remained grounded for three hours.

Why did it happen?

  • The passage plan was not correctly entered, due to unfamiliarity with the system being used. It was not checked after entry
  • The OOW relied too heavily on one single means of navigation and failed to check the passage plan inputted into the ECDIS.
  • The ECDIS chart scale settings were incorrect for the area the vessel was in, leading to inaccurate readings that drew it into shallow water
  • The audible alarm on the ECDIS was not operational, which meant that the OOW and lookout were not warned about the ship’s impending grounding

What changes have been made?

  • Recommendations have been made aimed at improving and standardising the use of ECDIS as a primary means of navigation
  • Improved training around situational awareness, watchstanding and teamwork on the bridge has been implemented.
  • Recommendations have also been made to the ECDIS manufacturer in question aimed at improving its functionality and ensuring safeguards are in place to reduce the likelihood of similar incidents occurring in the future.

THE ECDIS CHART SCALE SETTINGS WERE INCORRECT FOR THE AREA THE VESSEL WAS IN, LEADING TO INACCURATE READINGS THAT DREW IT INTO SHALLOW WATER

The Nautical Institute’s Mariners’ Alerting and Reporting Scheme (MARS) - https://www.nautinst.org/resource-library/mars.html - comprises a fully searchable database of incident reports and lessons, updated every month. If you have witnessed an accident or seen a problem, email Captain Paul Drouin at mars@nautinst.org and help others learn from your experience. All reports are confidential – we will never identify you or your ship.

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