Rogue Waves

Rogue waves (also known as freak waves, monster waves, killer waves, extreme waves, and abnormal waves) are relatively large and spontaneous ocean surface waves that occur far out in sea, and are a threat even to large ships and ocean liners. In oceanography, they are more precisely defined as waves whose height is more than twice the significant wave height (SWH), which is itself defined as the mean of the largest third of waves in a wave record. Therefore rogue waves are not necessarily the biggest waves found at sea; they are, rather, surprisingly large waves for a given sea state. 

            

On March 3, a sudden wall of water hit a cruise ship sailing in the Mediterranean Sea off the northeastern coast of Spain, killing two people, injuring 14 and causing severe damage to the vessel. 

You can read more here: Cruise-Ship Disaster article

Below are some links to some amazing, yet terrifying rogue waves.

1. A real rogue wave video
2. Deadly Rogue Waves Rock Cruise Ship
3. Spectators hurt by rogue wave