PORT CANAVERAL, Fla.—Terminal Three, a cavernous $155 million structure built for Carnival Cruises, is decked out with the company's signature blue paint, hundreds of beechwood seats and a posh VIP room with table lamps so new that sales tags still hang from some. It sits empty, near vast, vacant parking lots and fleets of idle shuttle buses. Sparsely populated hotels and restaurants surround what was once the world's second-busiest cruising port. Waylaid port workers scrape by on a mix of low-paying odd jobs and government help. "I never thought I would be standing in a food line for hours," said James Cox, a 50-year-old porter, who used to earn $27 an hour wrangling passengers and their luggage. "Just the degradation of it. You say to yourself, 'Wow, I am really at this point.' " Like the rest of the maritime tourism industry, Port Canaveral was mothballed at the start of the coronavirus pandemic. One year on, as other parts of the economy blink back to life, the U.S. cruise industry is waiting anxiously for Washington's go-ahead to sail again—and worried that a second summer season is about to be lost. Other countries including Singapore, Italy and the U.K. have authorized cruises or set a clear target date for them to set sail. Almost 400,000 passengers have sailed since some countries first began allowing cruises in July 2020, according to the industry's trade group. But to get started in the U.S., the cruise industry needs direction from the Centers for Disease Control and Prevention. The CDC lifted its no-sail order in October and replaced it with a conditional set of rules; industry officials say the 40 pages of rules are either indecipherable or impractical, such as a measure requiring cruise lines to conduct "simulated voyages" with volunteer passengers. "I refer to it as the 'impossible-to-sail order' because no business could operate profitably," Capt. John Murray, Port Canaveral's chief executive officer, said. The CDC said guidance is coming soon. "Future orders and technical instructions will address additional activities to help cruise lines prepare for and return to passenger operations in a manner that mitigates Covid-19 risk among passengers, crew members," spokesman Jason McDonald said in a statement, declining to comment further. A White House spokesman didn't respond to a request for comment. The order was written before vaccines were approved, and the CDC hasn't said whether it will revise the guidance to incorporate vaccinated crew and passengers.