on our way to Dutch Harbor in the Aleutians in 1984 on a USCG icebreaker...we had 60 plus footers for at least a day......I think it might have been close to 3 days....
had more foot prints on the bulkheads than the decks as we rolled up to 60 degrees..... way more than I prefer...
pic #1 is of a weather deck some 15 to 20 feet above the waterline ( tilt computer till horizon is level..
.....a wave one night broke out a window 80 feet above the waterline (see plywood patch near upper right of bridge).....pic #2.
also...the nice ice that looks like frosting on the cake....
60 footers in the North Pacific I would think are not common but not all that iregular.