Rogue Waves Are Over Twice the Size of Nearby Waves

For centuries sailors told stories of sudden walls of water appearing out of nowhere. NOAA’s National Ocean Service says these rogue, freak or killer waves were part of marine folklore for centuries, but have only been accepted as real by scientists over the past few decades. Scientists call them extreme storm waves and define them as waves greater than twice the size of surrounding waves. They are very unpredictable and often come unexpectedly from directions other than the prevailing wind and waves. Witnesses describe them as walls of water, often steep-sided with unusually deep troughs. NOAA’s page shows one estimated at 60 feet, or 18.3 meters, in the Gulf Stream off Charleston, South Carolina. Exactly how and when rogue waves form is still under investigation, although several causes are known.