"Once in 1,300 years" monster rogue wave recorded off Ucluelet on Vancouver Island

It would have been the ride of a lifetime for any nearby Long Beach surfers—or maybe their last wave ever.

A monster so-called rogue wave recorded off Vancouver Island measured 17.6 metres (58 feet) in height when it was recorded by a sensor buoy moored seven kilometers off Ucuelet, B.C., in November 2020.

The wave's proportional height to the seas around it meant that it was the largest-ever recorded rogue wave.

Research confirming the rare "once in 1,300 years" behemoth was only published on February 2, 2022, in Scientific Reports, an open-access science journal that publishes peer-reviewed science and engineering papers.

A rogue wave is defined as a wave that is at least twice the height of the waves that came both directly before and after it.

Although taller waves have been noted before, their heights were only twice the height of waves around them—such as the first rogue wave ever recorded, the 25.6-metre "Draupner wave" off Norway in 1995.

The Ucluelet wave, however, was triple the size of the surrounding waves.

"Proportionally, the Ucluelet wave is likely the most extreme rogue wave ever recorded," Johannes Gemmrich, the research paper's lead author, said in a February 8 statement. "Only a few rogue waves in high sea states have been observed directly, and nothing of this magnitude. The probability of such an event occurring is once in 1,300 years."

The buoy that recorded the wave is moored in water 45 metres deep on Amphitrite Bank off the west coast of Vancouver Island, one of a network of 26 such buoys around North America that are owned and managed by Victoria-based MarineLabs and comprise its CoastAware platform.

The buoys are capable of recording data in 20-minute segments every half-hour.

MarineLabs CEO Scott Beatty said in the February 8 statement that one goal of such information-gathering is to be able to predict such waves in the future.

"The unpredictability of rogue waves, and the sheer power of these 'walls of water', can make them incredibly dangerous to marine operations and the public," Beatty said. "The potential of predicting rogue waves remains an open question, but our data is helping to better understand when, where, and how rogue waves form, and the risks that they pose."

The authors of the research paper, Gemmrich and Leah Cicon, are both with the University of Victoria. Gemmrich is a physical oceanographer and an expert on surface waves and air-ocean interactions and is working on a project to protect beachgoers by being able to better predict extreme wave events. Cicon is a master student studying waves and wave models in order to be able to predict rogue-wave risk for the B.C. coast.

Rogue or extreme waves are a well-known hazard on the west coast of Vancouver Island. Visitors to Pacific Rim National Park Reserve, which contains the world-famous Long Beach, are warned to constantly be on the lookout for such waves because of both the extreme hazards they represent and the fact that they can appear out of a relatively calm sea.

During times of large ocean swells, storms, and coincident high tides, park visitors are warned by special extreme-wave advisories issued by Parks Canada.

In 2018, a UBC biology professor, Denis Lynn, was killed by a rogue wave while collecting shellfish samples on Calvert Island, off the northern tip of Vancouver Island.