Pants-wettingly scary, in fact.
This video from one Stev Golden allegedly shows what it was like to be on a ship off the south coast of Ireland on February 1st when we were in the beginnings of the battering we took from the Atlantic this year. Apparently these giant waves aren't an optical illusion and were as high as 52 feet, or two two-story houses on top of each other according to Golden.
It's a cycle of 'Oh God we're going to die, oh thank Jesus we didn't, oh God here we go again', lathered, rinsed (thoroughly) and repeated. We're getting seasick just watching it, and also developing a genuine fear of the ocean and never going on a boat again.
If you're impatient, skip ahead to the three and a half minute mark for the serious wave action.
Via Reddit