The high-speed catamaran Sleipner was carrying 89 passengers and crew when it split apart and sank on Friday evening after being skewered on a rock at the entrance to Boemla fjord, about 190 miles west of Oslo, one of the toughest stretches of a long coast known for its savage winter weather.
Eleven people were confirmed dead, while nine others are missing. Some of the survivors plucked from the sea or life rafts remain in serious condition in hospital, suffering from hypothermia.
The search was hampered by rain, huge waves, cold and wind that whipped the ocean into a frenzy of foam. Experts said survivors could only last for 30 minutes in such conditions.
Most of the victims were believed to be Norwegian.
It was the worst maritime accident off Norway since 158 people died when the Scandinavian Star caught fire south of Oslo after a suspected arson attack in 1990.
The investigation is likely to centre on the crew's reported attempts to refloat the vessel which, rather than any design fault, may have contributed to the vessel's sinking. Catamarans are double-hulled vessels, in theory making them safer than conventional vessels.
A delay of almost an hour between the grounding and the sinking gave passengers, who had been travelling from Stavanger north to Bergen, vital time to put on life jackets or scramble into life rafts.
But some survivors criticised the crew's efforts, claiming they had to take charge of the evacuation and that some of the crew allegedly did not know how to operate the life rafts. "We heard a bang," said one survivor, Haavard Rossland. "But it wasn't like the boat wrenched to a halt. We didn't get any information about what happened.
"Then there was panic. It was like the film Titanic. I saw the Titanic before me."
The Sleipner, operated by HSD, a Norwegian ferry company, is said to have an ultra-modern design. It only entered service in August this year, and had a cruising speed of 36 knots. It was custom-built to sail through fjords and equipped with the latest high-tech navigation and rescue equipment.
"The boats we use are new, with top modern equipment," said a spokesman for HSD, who added that bad weather was unlikely to have caused the accident. "It's incomprehensible that this could happen."
The vessel, made by the Australian firm Austal Ships, based near Fremantle, Western Australia, is thought to be a prototype. John Rothwell, chairman of Austal, said: "I would like to think the cause is more likely to be crew or pilot error than the fault of the vessel."
This spring Irish Continental Group, the ferry company, began running a high-speed pounds 24m catamaran from Dublin to Holyhead. The catamaran, bought from Austal Ships, has a capacity for 800 passengers - double that of the Norwegian vessel - and 200 cars for the two-hour crossing. No one from the company was available for comment.
Sea Containers, which owns Hoverspeed, operates seven catamarans made by another Australian firm, Incat, under the Sea-Cat livery across the English Channel and the Irish Sea.
Though catamarans can sail in rough waters, those in Britain will not sail in sea swells above 11ft for reasons of passenger comfort.
"There is an inherent safety in having two hulls rather than one," said a spokesman for Hoverspeed. "If a traditional single hull ship is ruptured, that is potentially more risky.
"Anything that travels on water carries an element of danger, and no one can claim their vessels are completely unsinkable. This accident happened when the catamaran hit rocks. That is what the inquiry will centre on."Reuse content