But rogue waves are not exactly solitons. Osborne says that they lie somewhere in the hierarchy between sine waves and solitons. His first glimpse of one came in 1999, when he saw a graph of the data on a wave that had struck a drilling rig in the North Sea on New Year’s Day in 1995. The wave was 85 feet high and half as broad as a football field. It arose out of a storm-tossed sea of 30-foot waves and swept across the deck of the rig at 45 miles per hour.
It was perhaps the largest ocean wave ever measured. By the high standards of the Norwegian oil industry, it was an event that occurs only once in 10,000 years. The U.S. Coast Guard considers rogue waves so rare that it doesn’t even keep records of their occurrence. Yet maritime records are filled with stories of fishermen and sailors who claim to have been struck by them. Some of these stories are probably exaggerated. As one marine insurer put it, “If a captain loses a ship or crew in rough waters, they blame it on a rogue wave rather than admit they were out when they shouldn’t have been out.” But many rogue stories are not exaggerated.
Reports from the Norwegian and British shipping industry suggest that rogue waves sink one supertanker or freighter every year. Rod Rainey, an engineer who investigates ship damage, told the BBC that a storm wave 12 meters high hits a ship with a force of 6 tons per square meter. A ship can take a hit of 15 tons per square meter without damage; 30 tons per square meter will dent it. A rogue wave can bring 100 tons per square meter down on a ship. “That,” says Rainey, “will hole it.”
One of Osborne’s favorite descriptions of a rogue wave is from Virgil’s Aeneid: “A squall came howling from the north-east, catching the sail full on, raising the waves to the stars, breaking the oars in a single blow, wrenching the boat around to offer its flank to the waves as a mountain of water rose above them, immense and immeasurable.