The chief executive of Norwegian Cruise Line Holdings on Monday rolled out a plan to start sailing again from the United States with fully vaccinated passengers and crew. A big catch: He still needs the Centers for Disease Control and Prevention to sign off, more than a year after the agency prohibited cruising in the United States.

The move by CEO Frank Del Rio is a bold salvo amid the cruise industry’s escalating frustration with the CDC, whose allegedly “outdated” rules have been the target of complaints in recent weeks. The criticism has only mounted since Friday, when the agency said travel for vaccinated people was low risk — but also laid out a raft of additional conditions, under a “conditional sailing order,” that cruise lines need to meet before getting permission to operate from U.S. ports.

“I’d like to hear an argument why we couldn’t sail,” Del Rio said in an interview. “If everyone on board is vaccinated and following the protocols, there is absolutely no need for the conditional sail order to exist as it is known today.”

Del Rio made his case to the CDC in a letter dated Monday.

The company, which includes 28 ships spread across Norwegian Cruise Line, Oceania Cruises and Regent Seven Seas Cruises, proposed starting to cruise again on or around July 4 with vessels at 60 percent capacity. In addition to the vaccine requirement for passengers of all ages, the company will require negative coronavirus tests, face coverings, contactless food service and other measures.

Del Rio called the combination of safety protocols and the vaccine requirement “just an unbeatable airtight set of circumstances that will make cruising a very safe vacation alternative.”

He said the operator had been working on the plan for some time and was reassured by the CDC’s guidance Friday about vaccinated travelers. The agency’s latest instructions for cruise lines, however, were not so well-received. The guidance recommended that cruise passengers, crew and port workers be vaccinated, but it also included multiple additional requirements regardless of the vaccination status of those on board.

“We were disappointed,” Del Rio said. “We thought it was a step backward, quite frankly.”

Last month, the Cruise Lines International Association urged the CDC to let ships start sailing from U.S. ports again by early July. The trade group again urged the agency to lift its conditional sailing order on Monday, calling the latest requirements “unduly burdensome, largely unworkable” and “at odds with the approach the CDC and governments in other parts of the world apply to all other travel and tourism segments in mitigating the risk of covid-19.”

Florida Gov. Ron DeSantis, a Republican, threatened to file a lawsuit if cruises continued to be blocked this summer, according to several media reports. Del Rio copied DeSantis and other elected officials from Florida, home to the world’s busiest cruise ports, on his letter.

“This impasse has got to stop,” Del Rio said. “The cruise industry must participate in the great national reopening. Every other hospitality travel and tourism sector has been allowed to operate and we have not.”

In a statement, the CDC sounded unmoved by Del Rio’s request, reiterating the approach it has laid out in its order.

“Cruising safely and responsibly during a global pandemic is difficult,” the statement said. “While cruising will always pose some risk of COVID-19 transmission, following the phases of the conditional sailing order will ensure cruise ship passenger operations are conducted in a way that protects crew members, passengers, and port personnel; particularly, with emerging COVID-19 variants of concern.”

Other cruise lines have announced plans to start cruising again for Americans outside the United States — including the Bahamas, Bermuda, Caribbean and Greece. In most cases, those cruises will require either everyone on board or those 18 and older to be fully vaccinated.

“We are the first taking this bold step to reopen cruising in the United States,” Del Rio said.

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