Cruise News Briefing - May 13, 2021. The CDC has updated its guidelines for cruise ships, including not wearing a mask when outside if vaccinated. Also, vaccinated guests can take independent shore excursions. Royal Caribbean announced that no masks will be required on its private island of Perfect Day at CocoCay. Norwegian Cruise Line detailed its brand new cruise ship on Wednesday that’ll debut in 2022. Two Carnival Cruise Line ships — Carnival Sensation and Carnival Liberty — are vaccinating crew in Mobile, Alabama and Port Canaveral, Florida. Cruise line stocks are down for CCL, RCL, and NCLH.