The disappearance of a key piece of navigational equipment from a Connemara fishing vessel after it grounded with the loss of four lives in September 2004 has hampered the official investigation into the incident.
Lack of sufficient evidence from the wreck of the St Oliver means the precise cause of its loss while en route from Carna to Rossaveal, Co Galway, remains "shrouded in obscurity", according to the Marine Casualty Investigation Board.
The vessel's global positioning system (GPS) receiver, which was seen on board the wreck during the initial stage of the board's inspection, "went missing" when efforts were made to recover it, the report says.
"The significance of the GPS equipment cannot be played down as this unit could reveal the path taken by the vessel prior to grounding," the report emphasises.
The skipper-owner of the St Oliver, Aran islander John Dirrane - and his three crew of Michael "Sonny" Faherty (41), also from Inis Mór; boatyard owner Josie Connolly (66), from Leitir Ard, Co Galway; and Michael Mullen (18) from Clifden - died when the 19m vessel broke up on rocks at Duck Island less than two hours after leaving Carna on the night of September 17th, 2004.
The bodies of three of the men were recovered close to the wreckage in the hours after the grounding. Mr Dirrane's body was found a week later.
Mr Connolly's widow recalls in the report that her husband stated he "would not fancy going out on the boat, as he knew that the weather was bad with a big sea running". The boat had been under repair in Mr Connolly's yard for 17 days, and the owner would have been under severe pressure to return to fishing.
Mr Connolly was asked to accompany the crew on the 25 nautical mile journey to Rossaveal just before the boat's departure at 7.15pm, because of his local knowledge of the area.
The only communication that there was anything amiss on board was reflected in a mobile text message, sent by crewman Michael Mullen at 8.23pm, in which he told a friend the seas were very rough, and indicated that the vessel's two computers were down and, in the words of the report, that "there seemed to be an element of doubt about the boat's position".
No radio distress signal was issued by the vessel, but the alarm was raised by the Coast Guard when it picked up a signal from the boat's emergency position-indicating radio beacon at 9.03pm. The beacon was retrieved by a helicopter winchman in the early hours of September 18th, and it appeared to have been activated manually. It remains unclear as to why a radio distress call was not made.
The investigation concludes the chart plotter and either the radar or GPS were not working properly, and this may have been the result of a circuit breaker activating or a short circuit in the system.
"The reasons behind the loss of the St Oliver will never be known but it should, if for no other reason, reinforce the need for all mariners to prepare for every voyage properly by adhering to the basic principles of voyage planning," the report says.
