Tsunamis at sea!

Monster Waves Rule the Seas (ScienceNOW -- Bosch 2004 (726): 2)

Sailors often whisper of monstrous waves capable of sinking the most seaworthy ships, but oceanographers have written off such reports as exaggerations. Now a satellite study has turned up evidence that freakishly large waves are more common than scientists thought.

Within the past 2 decades, at least 200 cargo ships--200 meters or more in length--have been lost at sea. Eyewitnesses and survivors describe huge breaking walls of water, more than 25 meters high, sometimes rising up out of calm seas. Such freak waves and the conditions that cause them are poorly understood. Mathematical models suggest that the waves should occur only once every 10,000 years on average, but recordings from buoys and offshore oil platforms suggest they're much more common.