The designer of Sleipner, the high-speed ferry that hit rocks and sank off Norway, said that the accident was a freak and insisted that the ultra-modern catamarans were safe. Asbjoern Tolo said the ill-fated boat must have suffered unusually severe damage from the collision in rough seas that punctured both hulls. "This type of vessel is safe but freak things like this happen," Tolo said. The two aluminum hulls of the Australian-built catamaran, which had a capacity of 358 passengers and a top speed of about 36 knots, each had seven airtight compartments. Under international regulations, the ship should be able to sustain damage to two compartments in each hull without sinking.