Cruise News Briefing - May 6, 2021. The U.S. Centers for Disease Control issued new guidance for cruise lines to restart service. Carnival Cruise Line announced that every cruise ship in its fleet will receive a blue hull like the upcoming Mardi Gras. Holland America Line said on Wednesday that they will begin sailing this summer from Greece with the Eurodam. Princess Cruises is making new changes to its dining program once they resume sailing again. Cruise line stocks for CCL, NCLH, and RCL.