The Centers for Disease Control and Prevention confirmed it would transition to a voluntary program for COVID-19 mitigation on cruise ships Wednesday.
But "voluntary" doesn't mean that cruise ships will not be regulated by the CDC – regardless of whether they opt into the program, according to Capt. Aimee Treffiletti, who leads the CDC's maritime unit.
Cruise ship operators "can choose the 'healthy sail' option, or they can choose to kind of do their own thing, but it's very important to keep in mind that ships will still be under CDC's regulatory authority," Treffiletti told USA TODAY on Friday.
If a cruise line chooses to opt out of the program, its ships would then fall under the CDC's mask order for public transportation and the agency's regulatory authority for inspections. And cruise ships, regardless of participation in the voluntary program, will still be required to report every COVID-19 case on board, just through a "different mechanism" than the way they now report cases.
►'They're not giving us any information': Norwegian cancels sailing mid-cruise, passengers don't know when they'll get home
And if the CDC is concerned about COVID-19 on a ship that isn't under the new program?
"I think (we) will be probably quicker to exercise our regulatory authority," Treffiletti said. "Because, you know, we won't know what's happening on the ship as far as the mitigation measures."
The CDC reserves the right to issue a "no sail" order for a particular ship if the agency has concerns about what is happening on board.
►CDC monitoring cruise ships for COVID: Here's how to check whether your ship is on the list
►'Avoid cruise travel': CDC warns travelers after more than 5,000 COVID cases in two weeks amid omicron
It's in the best interest of public health for lines to volunteer to follow the "healthy sail" program, Treffiletti said. She noted that the program will provide transparency about levels of COVID-19 on board and how the pandemic is being managed, while ships that don't opt in won't have to make public how they are managing the coronavirus on board.
"There will be a lot of unknown about what risk mitigation measures are being used on board because they will really be able to set their own protocols for testing of passengers and crew," Treffiletti said, noting that isolation protocols and other health measures will not necessarily be made public, either.
Cruise lines that opt for vessels to follow the voluntary program will be following what are known by the CDC to be "the best public health standards" for cruise ships.
The CDC has not yet made public the details on the new voluntary program but expects to next week.
Norwegian, Oceania, Regent Seven Seas cruise lines opt in to CDC's voluntary program
Norwegian Cruise Line Holdings Ltd., parent company to Norwegian Cruise Line, Oceania Cruises and Regent Seven Seas Cruises, told the CDC all of its brands would participate in the voluntary program on Friday, Treffiletti said.
Frank Del Rio, president and CEO of Norwegian Cruise Line Holdings Ltd., said in a statement Friday that the decision to commit to the CDC's program furthers the line's commitment to health and safety.
"Our adoption of the voluntary program provides guests, crew, travel partners and other stakeholders with the assurance that our brands will continue to meet and exceed the provisions laid out by the CDC and provide unparalleled health and safety protocols not found in any other sector of the travel and leisure space," Del Rio said.
As of Friday, other cruise companies have until Jan. 21 to decide whether they will partake in the voluntary program or not. That date, however, could be subject to change, according to Treffiletti.
"The CDC is committed to continuing to work with a cruise industry," she said. "We do hope that cruise lines choose to follow this program, because it does represent the best public health measures to help prevent illness onboard, and COVID transmission, as well as severe outcomes."
The CDC still advises travelers against cruising, regardless of their vaccination status, as COVID-19 continues to surge with the emergence of the omicron coronavirus variant.
►'We found out while we were flying': Last-minute cruise cancellations leave travelers scrambling
►Cruising during COVID-19: Cancellation, refund policies vary by cruise line
This article originally appeared on USA TODAY: COVID on cruises: CDC program voluntary but agency will still regulate