Cruise ships could set sail by mid-July, CDC says Some of the agencyâs most difficult terms will be relaxed if there is a high vaccination rate among the crew and passengers. Â Â The Carnival Pride cruise ship arrived at PortMiami April 7, 2020, in Miami as the cruise ship industry extendd the suspension of U.S. sailing operations. The CDC says they could set sail again by mid-July if there's a high vaccination rate among crew and passengers. [ LYNNE SLADKY | AP ] By Sun Sentinel Updated Apr. 30 Cruising could resume operations from U.S. ports by mid-July aboard ships with at least 98 percent of the crew and 95 percent of passengers fully vaccinated, the nationâs top health protection agency announced.