For centuries, mariners have spun tales of gargantuan waves, 100-feet high or taller. Until recently scientists disƯmissed these stories--waves that high would seem to violate the laws of physics. But in the past few decades, as a startling number of ships vanished and new evidence has emerged, oceanographers realized something scary was brewing in the planet's waters. They found their proof in February 2000, when a British research vessel was trapped in a vortex of impossibly mammoth waves in the North Sea--including several that approached 100 feet.