Petra...it had no characteristics of a tsunami...it was a rogue wave...and not all that rogue, more like just an extra big one in the middle of high seas...
The westher channel (or somewhere) suggested it was only 50 feet but that the ship was rolling so it could break windows higher up the ship...makes sense.

During the perfect storm in 1991 a buoy recorded a 100 foot (30 m) wave...off of New England...
Chris