An enormous wave roughly the height of a four-story building is believed to be the most extreme rogue ever recorded according to a recent paper. The marine beast surged through waters off the west coast of Vancouver Island in 2020 where it was picked up by open ocean buoys.

The dramatic wave height at Amphitrite Bank, where the buoy was deployed, was recorded and the data collected by Marine Environmental Data Section. Using this information, the authors behind a paper published in Scientific Reports were able to carry out rogue wave models, simulations, and predictors to establish the “Ucluelet wave” was almost three times the height of surrounding waves at 17.6 meters (57.7 feet).

Rogue waves are characterized by being extremely out of step with the waves around them, described as the “wave field”. While the Ucluelet wave isn’t the tallest wave height ever recorded, this rogue wave is thought to be the most extreme ever recorded owing to its relative size.

“The Ucluelet wave had an absolute wave height of 17.6 meters [57.7 feet] and a crest height of around 12 meters [39.3 feet], when the background wave field was 6 meters [19.7 feet],” said study author Dr Johannes Gemmrich of the University of Victoria to IFLScience.

“So, the normalized wave height was around three and the normalized crest height around two. The greater the normalized wave height, the less likely such an event is. All other rogue waves reported so far had normalized heights at 2.2 to 2.5, which makes them two to three orders of magnitude more likely.”

Using Second Order Theory, the standard for estimating the occurrence rate of extreme waves, says Gemmrich, the researchers established that the Ucluelet wave was a one in every 1,300 years kinda wave. Truly a shiny in the Top Trumps of Rogue Wave.

All sounding very impressive, then, but what’s the real world significance of this information for people at sea? Can a freighter cope with a wave field in which one rogue wave is surging at well over double the height of the rest? In the case of the 17.6 meter [57.7 foot] Ucluelet wave, just about, but it would be a nasty surprise.

“Large vessels and offshore structures are built to withstand 18 meter [59 foot] waves,” explained Gemmrich. “The danger is to smaller vessels. In a 6 meter [20 foot] sea state the vessel operator would not expect an 18 meter [59 foot] wave.”

The researchers behind the discovery have since used data on the Ucluelet wave to apply a new rogue wave risk forecast, which they developed in collaboration with the Nils-Bohr Institute.

“We hope to bring this forward to an operational forecast implemented by the national weather services,” Gemmrich concluded.

[H/T: Victoria Buzz]