CDC's Guide to Cruise Ships Operating in the U.S. UU. Much of the new guide is optional. CDC recommends that cruise lines require passengers to undergo pre-boarding tests no more than three days before sailing, but strongly recommends that lines require testing one day after boarding.
That guidance comes as some cruise companies have indicated plans to stop pre-shipment testing in the coming weeks, including Azamara and Norwegian Cruise Line Holdings. CDC also recommended that travelers check directly with their cruise line about Covid testing and vaccination protocols before traveling, and that they choose to get tested even if the cruise line doesn't require it.