The UK's sea safety body has warned that computerised navigation systems are steering large vessels into dangerous shallows because officers have insufficient training in their use.

The Department for Transport's Marine Accident Investigation Branch (MAIB) sounded the alert after over-reliance on an incorrectly used Electronic Chart Display Information System (ECDIS) resulted in the temporary grounding of the cargo ship Performer on Harborough Sand on its way to Grimsby in May 2008.

A subsequent investigation by MAIB warned: "The use of ECDIS has steadily increased in recent years, and it is disturbing that the number of accidents resulting from the incorrect use of ECDIS and ECS [Electronic Chart Systems] through poor system knowledge has also risen.

"ECDIS will soon replace paper charts as the primary planning and monitoring media onboard most vessels, but the system can only realise its potential benefits to maritime safety if all mariners who are expected to use the equipment at sea are properly trained."

Many ships' officers, including the master of Performer, were only formally trained in the use of paper charts, although many have used electronic aids. An ECDIS installed in 2007 was Performer's primary means of navigation, but none of her bridge watchkeeping officers had been trained in its use.

MAIB cited a number of accidents in recent years in which misuse of ECDIS or ECS has been a contributing factor, including a cross-Channel ferry that headed for shallows in 2004 without its ECDIS issuing a warning because it had not been correctly set up.

And in January last year a vessel hit a submerged wreck near Dover, severely damaging her propellers, because the wreck was not shown on the ECS display.
"The need for mandatory training in ECDIS is compelling," said the MAIB report.

Proposed international regulations require ECDIS in most large new passenger vessels and large cargo boats and tankers, and its retro-fit over time to existing vessels.