Stena Line expects that its pride and joy, the Explorer high speed catamaran, will be out of service for some time on the Dun Laoghaire-Holyhead route following yesterday's accident.
The company was unable to quantify the cost of the damage to the aluminium hull of the £65 million vessel. "There was never any danger to life, as the vessel is equipped with buoyancy berths," a spokesman stressed.
Berthing by Global Positioning System (GPS) navigation in Dun Laoghaire can often be affected by windy conditions, and yesterday's north-north-easterly, gusting 40 knots in the harbour, caused a considerable swell.
The mooring dolphin which the vessel struck was one of a series installed recently to help the catamaran's berthing.
The high speed catamaran has been plagued by difficulties since it was introduced, but the craft's success can be judged by the fact that Stena's rival, Irish Ferries, has ordered a £29 million catamaran for its Dublin-Holyhead route. It is being built in Australia.
The Stena catamaran aroused much scepticism when it was at the design stage, and its introduction on the Irish Sea was delayed several times.
The first deadline was missed in 1995, due to delays at the shipyard in Finland. Its deadline in March 1996 was set back on foot of tests by the UK marine safety authorities.
The ship, with a capacity for 1,500 passengers and 375 cars, made its first 99-minute crossing in early April 1996, after the UK marine agency approved the use of emergency escape chutes.
Local concerns about increased freight traffic generated by the new Dun Laoghaire ferry were allayed somewhat when the then minister of state for the marine, Mr Eamon Gilmore, secured the company's agreement to divert some freight to Dublin port.
Teething problems continued to crop up, however, including complaints from Howth, Dun Laoghaire and Killiney bathers about large waves generated by the vessel on the approach.
A naval architect was engaged to "play King Canute", following a potentially serious incident at the Irish Lights depot in Dun Laoghaire when seas were reported to have surged towards the dock where navigational buoys are stored.
The wave was caused by sub-surface pressure generated by the 40 knot catamaran, and complicated by the presence of two sandbanks - the Burford and Kish - off Dublin Bay. Wave velocity increases in shallow water; in other words, sandbanks generate rougher seas.
During trials, the HSS agreed to halve its speed on the approach from the Burford Bank.
However, further marine safety regulations restricted the vessel; it cannot leave port when waves are more than four metres high.
A Stena spokesman said yesterday there had been a 98 per cent success rate in sailings up to Christmas, with bad weather over and after the holiday period then reducing this to 92 per cent reliability.
When the catamaran cannot sail, passengers travel on Stena Line's Challenger from Dublin port.
Yesterday's incident comes at a time when competition between Irish Sea ferry companies is increasing. Merchant Ferries has announced twice daily sailings to Liverpool, and Sea Containers is introducing a new Super Sea-Cat craft in April.
