Scientists have confirmed that a four-story-high wave recorded off the west coast of Canada was the most extreme rogue wave ever officially documented. The wave, which occurred near Ucluelet, British Columbia, was roughly three times the height of the waves surrounding it. It did not cause any injuries or damage. Researchers at the University of Victoria analyzed the data and confirmed it was not a technical error.

Rogue waves have been part of maritime lore for centuries, but scientists only officially recognized them in 1995. That year, the Draupner wave, measuring 84 feet, struck a Norwegian gas platform in the North Sea. The platform was designed to withstand waves up to 64 feet. Since the wave did not match any known wave model, researchers formally defined a rogue wave as one that is more than twice the height of the waves around it.

Rogue waves can form in stormy seas or appear in calm water without warning. They have steep sides, deep troughs, and can reach heights that pose serious risks to ships and offshore structures. In 2007, the National Oceanic and Atmospheric Administration compiled a list of 50 historical maritime disasters that were likely caused by rogue waves. One example is the 1975 sinking of the freighter Edmund Fitzgerald on Lake Superior, which some experts attribute to a phenomenon known as the Three Sisters, a sequence of three large waves.

Scientists have proposed two main explanations for how rogue waves form. The linear addition theory suggests that waves traveling at different speeds can cross paths and combine their energy into a single larger wave. The nonlinear focusing theory proposes that waves moving in groups can exchange energy, and that transfer can produce a rogue wave. A 2024 expedition to Antarctica by researchers from the University of Melbourne provided new evidence that strong winds over young waves play a significant role. The scientists used 3D cameras to track wave behavior and found that rogue waves occurred roughly once every six hours in windy conditions and did not appear in calmer seas.

In 2018, researchers recreated the Draupner wave in a laboratory for the first time. Their work showed how waves approaching from different directions can push water upward and form what is called a crosswave. Unlike ordinary waves that stop growing when they break, crosswaves can continue to grow even after breaking. The study found that waves meeting at large angles can become up to four times steeper than previously thought possible. This finding has implications for the design of offshore structures, such as wind turbines and oil platforms, which may not currently account for multidirectional wave forces.

Rogue waves are distinct from tsunamis. Tsunamis are caused by large-scale disturbances such as earthquakes, volcanic eruptions, or landslides that displace the entire water column. They are barely noticeable in the open ocean but can become destructive near shorelines. Rogue waves, by contrast, form at the surface and can appear without any seismic trigger.

Researchers have also identified a separate phenomenon called internal rogue waves, which form deep below the ocean surface. While the exact frequency of future rogue waves remains uncertain, scientists note that increased energy in the atmosphere and ocean could lead to more powerful waves in the coming years.