The Magic and Wonder go into drydock every2-3 years. The Dream and Fantasy every 5, until they are 15, and then most likely will revert to every 2-3 not to exceed 3 years, unless the rules change again.
an ocean going passenger vessel that takes on folks in a US port must undergo a drydock/underwater inspection twice in the past 5 years (sliding scale) there is a time for new construction b4 this kicks in .... SOLAS recommendations as written into US code and enforced by USCG.
and not the result of a recent change