Hurricane Ivan generated a wave more than 90 feet (27 metres) high - thought to be the tallest and most intense ever measured - scientists have revealed.
Satellite image of Hurricane Ivan south of western Cuba
It would have dwarfed a 10-storey building and had the power to snap a ship in half - but never reached land.
The wave was recorded by sensors on the ocean floor as Hurricane Ivan passed over the Gulf of Mexico last September.
The observations suggest prior estimates for extreme waves are too low, researchers warn in Science.
Hurricane Ivan caused more than 100 deaths and left a trail of devastation as it swept over several Caribbean islands and part of the United States.
As it moved over the Gulf of Mexico, it triggered sensors deployed by the Naval Research Laboratory to measure water pressure.
Scientists at the Washington-based laboratory in the US used the data to calculate the extreme waves created under the eye of the storm.
The distance between the crest of the biggest wave and its trough was 91 ft (27.7 metres) but they suspect the instruments missed some waves that were as tall as 132 ft (40 metres).
Hurricane Ivan left dozens dead in Grenada and its capital St George's
The waves were bigger than expected, suggesting theoretical models of waves whipped up by hurricanes may have to be revised.
"Our results suggest that waves in excess of 90 ft are not rogue waves but actually are fairly common during hurricanes," lead author Dr David Wang, told the BBC News website.
He said that since hurricane activity is predicted to increase over the next few decades, more research like this needs to be carried out.
The 91 ft wave was the largest individual wave measured with instruments in US waters, he added.
It echoes the wave depicted in the film, The Perfect Storm, which was 100 ft tall. The story is based on the 1991 storm off Gloucester, Massachusetts, which was one of the strongest in recorded history.