What Are Rogue Waves? Learn About This Dangerous Ocean Phenomena

The ocean is immense and powerful. Lifeguards, sailors, and marine scientists spend years training and studying to predict its changing tides. Among the most terrifying phenomena that can occur out at sea are rogue waves—which are waves that come out of nowhere and are over twice as tall as those surrounding them. Long thought to be a myth, these massive waves can be exceptionally dangerous. Understanding rogue waves is critical in a time of climate change, and particularly after a series of enormous waves pounds the coast of California in late December of 2023.

A rogue wave—known as a freak or killer wave—occurs in open ocean. While it may be too early to tell if the California waves are scientifically “rogue.” According to National Geographic, “Scientists do not completely understand how rogue waves form. One explanation is that wave trains travel thousands of miles across ocean basins, encountering other wave trains as they move. When the crest and trough of two different waves meet head-on, they can cancel each other out, resulting in a flat sea. But when two crests run into each other, they form a huge wave that is the sum of both wave heights—a rogue wave that towers above other nearby waves.” Fast ocean currents and violent storms that whip up winds can also make these waves more likely. Therefore, global warming is likely to make them more common as seas warm and weather becomes more unpredictable.

The first documented rogue wave was observed in 1995 off the coast of Norway. Known as the Draupner wave, it rose 25.6 meters (74 feet) above the water. This was slightly over twice the height of the nearby waves. However, the most extreme rogue wave ever recorded occurred in November 2020 off the coast of British Columbia, Canada, as reported in Scientific Reports. A MarineLabs buoy which rose and fell during the event recorded the wave, which climbed 17.6 meters, or almost 58 feet. While it was not the tallest on record, it was almost three times as tall as the surrounding waves. This made it more “rogue” than any previously recorded.

So, why track these waves? According to CEO Dr. Scott Beatty in a statement from MarineLabs, “We are aiming to improve safety and decision-making for marine operations and coastal communities through widespread measurement of the world's coastlines. Capturing this once-in-a-millennium wave, right in our backyard, is a thrilling indicator of the power of coastal intelligence to transform marine safety.”