If you haven’t seen the 1972 movie The Poseidon Adventure (it’s a classic, starring Gene Hackman, Shelley Winters, and Leslie Nielsen, among others!), perhaps you’ve seen the 2006 remake simply dubbed Poseidon, with Richard Dreyfuss and Kurt Russell. These movies tell the story of a cruise ship named after the Greek god of the sea, Poseidon, that is struck by a massive rogue wave and capsizes, turning completely upside down. Like most disaster movies, the premise is a bit unbelievable, but rogue waves exist, and scientists are finally gaining an understanding of how and why they form.

The legend of rogue waves has existed for centuries. Sailors would report monstrous waves that seemingly appeared out of nowhere. Despite the persistent stories, rogue waves weren’t scientifically measured until 1995, when an 80-foot wave in the North Sea hit the Draupner oil platform, wreaking havoc but ultimately becoming the first rogue wave ever measured in the open ocean. Myth became reality, but scientists still didn‘t understand how these waves formed.

Satellite data was first used to study rogue waves in 2001 using the European Space Agency’s ERS-2 satellite. Since then, there have been several studies internationally using satellites to better understand rogue waves and in late 2024, the Surface Water and Ocean Topography (SWOT) satellite captured waves measuring 65 feet to 115 feet. The data not only confirmed the existence of such massive waves but found that they can occur hundreds or even thousands of miles away from powerful storms. This data, along with other studies, has given scientists a better understanding of rogue waves than ever before.

Satellite data proved the existence of rogue waves, but we actually know much more. After the rogue wave hit the Draupner oil platform, Francesco Fedele, an associate professor at Georgia Tech’s School of Civil and Environmental Engineering, led an international team on an 18-year study of wave records in the North Sea. The team analyzed 27,500 wave records, and each record contained 30 minutes of wave activity, including how high the waves were, the frequency of waves, and their direction.

This research found that large waves typically occur in one of two ways: waves traveling at different speeds and different directions align and combine to form a much taller wave. This is called linear focusing. There’s also a second, natural process that stretches the shape of the wave to make it steep and tall but flattening the trough (the lowest point of the wave) which increases its height by up to 20%. Ultimately, Fedele hopes this research will help scientists predict when a rogue wave will happen.

The data has proven this old sailor’s myth, but you shouldn’t be worried about a rogue wave hitting your cruise ship — though it happens from time to time. In 1995, Cunard’s Queen Elizabeth 2 encountered an estimated 92-foot wave, but was able to steer into it, and no one was injured. Data has found they are much more common than previously thought, though the National Oceanic and Atmospheric Administration still calls them “uncommon.” Still, the likelihood that one would hit your cruise ship is low, and modern sailors know there are some parts of the ocean they should simply avoid.