About reports that a "26-foot rogue wave hit the Cyprus-based cruise ship the Louis Majesty today while the ship was sailing near the French Mediterranean port of Marseilles. Two passengers were killed and six others were injured. The Louis Majesty, operated by Louis Cruise Lines, was sailing from Barcelona to Genoa with 1350 passengers and 580 crew onboard."
According to Wikipedia,"rogue waves (also known as freak waves, monster waves, killer waves, and extreme waves) are relatively large and spontaneous ocean surface waves that are a threat even to large ships and ocean liners."
Rogue waves are mystery, explains the BBC:
... they shouldn't exist at all. Oceanographers and meteorologists have long used a mathematical system called the linear model to predict wave height. This assumes that waves vary in a regular way around the average (so-called 'significant') wave height. In a storm sea with a significant wave height of 12m, the model suggests there will hardly ever be a wave higher than 15m. One of 30m could indeed happen - but only once in ten thousand years. Except they do happen with startling frequency.Freak waves can "exert a pressure of 100 tonnes per square meter on a ship, far greater than the 15 tonnes that ships are designed to withstand without damage."
The South Atlantic is where many rogue waves have been reported. Previously, the only passenger ships to have encountered rogue waves in this century were the MS Bremen and Caledonian Star. In March 2001 these ships encountered a 30-meter (98 ft) rogue wave near Antarctica. The MS Bremen lost all power and instrumentation, and had power not been restored, the well-build German ship might well have sunk.
This YouTube video shows the recent rogue wave strike on the Louis Majesty. Watching it, keep in mind that waves always look much smaller when captured in photographs and video than in real life.