While still encouraging passengers to keep their masks on, major cruise lines are dropping mask mandates for fully vaccinated travellers indoors.The latest, Royal Caribbean International and Carnival Cruise Line will join Norwegian whose Norwegian, Oceania and Regent Seven Seas brands have already ditched mask requirements.

Virgin Voyages is also dumping its mask mandate, leaving only MSC Cruises and Disney Cruise Line still requiring passengers to be masked.

“We have had a very successful restart of guest operations thanks to the support of our guests, the commitment of our shipboard team, and the effective protocols we have put in place,” Carnival’s president, Christine Duffy, said in a statement. “The public health situation has continued to improve, providing confidence about these changes.”

Carnival’s new regulations go into effect March 01, as do Norwegian Cruise Line voyages that depart from US ports.

Royal Caribbean is making masks optional for vaccinated guests for voyages departing on or after February 25. “We expect unvaccinated children to continue wearing masks indoors and in crowded settings,” the cruise line said on its website.

The cruise lines agreed to participate in the Centers for Disease Control and Prevention’s voluntary Covid-19 program under which cruise lines may lift mask wearing requirements when 95 percent of passengers and crew members are fully vaccinated.

Guests will have to follow all local mask rules when ashore during ports of call.