rogue wave, a relatively unpredictable and unexpectedly high water wave arising at the water’s surface and formed from the coincidental stacking of multiple wind-driven wave crests passing through a single point or arising from a combination of waves and currents that may shorten the waves’ frequency. Rogue waves tower to heights greater than twice the size of nearby waves, and they may move in either the same direction, the opposite direction, or at oblique angles to the prevailing wind and wave motion. They may be hazardous to ships at sea, capable of capsizing a vessel or washing crew members off the deck and into the ocean, and they are powerful enough to damage oil-drilling platforms and lighthouses. Rogue waves are distinguished from tsunamis, which are caused by submarine earthquakes, underwater or coastal landslides, or volcanic eruptions.

　　Unusually high waves resembling present-day rogue waves were the subject of folklore for several centuries. Even reports of 30-meter (100-foot) waves from such reputable figures as 19th-century French explorer and navigator Jules-Sébastien-César Dumont d’Urville were not taken seriously by his employers. In fact, the first indisputable evidence of rogue waves did not become available until nearly the end of the 20th century, from scientists analyzing data recorded at the Draupner E oil-drilling platform off the coast of Norway in the North Sea in 1995. A laser wave gauge mounted on the platform measured a 25.9-meter (85-foot) wave as it crashed over the structure. That wave was twice the height of those that came before and after it as well as being 6.4 meters (21 feet) higher than could be explained by any wave model existing at the time (see also scientific modeling). The “Draupner wave” is the highest confirmed rogue wave known. The most extreme rogue wave on record, however, occurred in the Pacific Ocean near the coast of British Columbia in 2020. Although its height, at 17.6 meters (57.7 feet), was somewhat less than the Draupner wave’s, it was more than three times higher than surrounding waves.

　　More From Britannica What Makes a Wave Go Rogue? Unconfirmed reports of higher rogue waves also exist. One of the highest rogue waves is said to have occurred in 1933, when an estimated 34-meter (112-foot) wave crashed over the USS Ramapo in the North Pacific. Higher still was the wave that reportedly swept over a lighthouse at Trinidad Head, California, during the winter of 1914–15. The top of the lighthouse stood 53.3 meters (175 feet) above sea level, and records noted that the wave might have been as much as 61 meters (200 feet) high.