Lisa, I don't know this for sure but would imagine that holding the ship would mean rescheduling the departure time on the spot so they could widen the window to allow folks to board. That would require compliance by the Customs official at the pier who would have to stay to put his stamp on the finalized manifest when they did arrive. I just don't know and I'm sure the ambiguity is because the cruiselines don't know either. It is probably handled on a case by case basis until they get the bugs worked out of a new system. I'll let you know if I have an experience come up where a ship has been held and what happens.