I think that Todd has a point. Also, I might add that as more and more new ships are coming out, cruiselines could use their older ships to cross the Atlantic.
It would make sense for retirees who are tired of flying. With today's airline service and airport security flying is no fun at all.
Carnival Liberty New Year's Eve 2007
Liberty of the Seas 5/2008+11/2009
Allure 1/16/ 2011
Vision OTS 2-14-2015
Freedom OTS 3/6/16
Booked -Harmony of the Seas. 12/31/16