You have not heard a ship’s captain claim large waves didn’t exist. They have been well-known for centuries by captains and have been documented by scientists for 75 or more years...
...and yes, I liked the wave. :)
not quite admitted to ~ within 75 years ~ more like 25 years ~ check Peregrine soliton at http://www.nature.com/nphys/journal/v6/n10/abs/nphys1740.html or read the cute story about the Lego pirate in a fishtank at http://www.tgdaily.com/general-sciences-features/62516-lego-pirate-proves-existence-of-super-rogue-waves. I have to study that one a bit more because it suggests the existence of even bigger waves than anyone had thought possible. This stuff all derives from quantum expressions ~ not from ordinary hydraulic formulae.