The CDC has given cruises the go-ahead to set sail in the U.S. after months of uncertainty — but it could still be months before passengers are allowed on board ... The order — which applies to ships with the capacity to carry at least 250 passengers and travel in U.S. waters — details how cruise lines should take a "phased approach for the safe and responsible resumption of passenger cruises," making it clear that no passengers will be allowed to sail at this time.