But more than 15 months after the pandemic halted the industry, the first big cruise ship set sail out of a US port on Saturday.
Celebrity Edge left from Port Everglades in Fort Lauderdale just after 6 p.m. on a seven-night voyage with ports of call in Mexico and the Bahamas.
The ship is sailing at 40% capacity as Celebrity -- and the industry -- sets off toward a US recovery.
"For this start-up period, we're sailing with a reduced capacity to give us all a chance to get used to the protocols and to really allow for natural social distancing," said Susan Lomax, head of global public relations at Celebrity Cruises.
Kate McCue, the first and only American female captain of a mega-cruise ship, is at the helm.
A "fabulous experience" is what Stewart Chiron expects on board.
Chiron, a cruise expert behind The Cruise Guy website, was recently on a Celebrity Millennium cruise out of Sint Maarten, so he knows what to expect. "Vaccinated passengers will be able to put away masks while onboard. Going ashore in Mexico and the Bahamas will have restrictions but who cares! We're out on the high seas, cruising again. Jumping through a few hoops is not a big deal," Chiron said via email.
Some of Celebrity Edge's passengers were so excited to board they wore special t-shirts for the occasion.
"I ordered them because we needed to make a statement," said Cynthia Mitchell, of Hope, Kansas, wearing matching "Straight Outta Vaccination" shirts with her husband, James.
"I know we have all been through huge trauma, and everybody knows people who we have lost through this situation," Mitchell said. "I think it's good that Celebrity has got their folks back to working and ready to sail. I'm excited."
"I did cartwheels just a minute ago. That's how excited I am," said Tina Carter, of Washington, DC. "I'm really excited just to be back cruising. Nothing like it."
Vaccinated passengers and crew
All crew is vaccinated, along with at least 95% of passengers.
That's in line with CDC rules that say a cruise ship can either sail with nearly fully vaccinated passengers and crew, 95% in both cases, or conduct a trial cruise before sailing with paying passengers to test safety protocols.
While Celebrity Edge is in compliance with the rules, a federal court recently sided with the state of Florida, issuing a preliminary injunction barring the Centers for Disease Control and Prevention from enforcing its conditional sailing order in the state.
A ban on businesses requiring proof of vaccination in Florida has also called cruise lines' policies into question. Celebrity says asking about vaccination status is still permitted under the ban -- it just can't be required.
Celebrity passengers who opt out of providing vaccination information are considered unvaccinated and 5% of cabins have been set aside for those guests, according to Lomax. Unvaccinated passengers over 16 years old will be subject to additional Covid-19 testing at their own expense.
Parts of the ship will be designated for those who are unvaccinated, Lomax said, and unvaccinated guests will be required to wear masks or face coverings.
New measures to reduce Covid risk
Cruise lines have worked with health and medical experts, industry organizations and government officials to develop safety protocols in line with the rules and guidelines put in place by the CDC.
Aboard Celebrity Edge, staggered arrival and departure times are being implemented to avoid large groups. Most passenger cabins will be spaced out and crew members will have their own cabins because of reduced capacity.
People stand in line to board the Celebrity Edge cruise ship on June 26.
Maria Alejandra Cardona/AFP/Getty Images
Buffet meals, beloved by many passengers, will still be offered but they will be served by crew rather than self-service.
The ship will also have additional medical resources on board in case of an outbreak, including capacity for 33 patients and four ICU beds.
Outbreaks aboard ships early in the pandemic resulted in numerous deaths and hundreds of infections, but medical experts consider widespread vaccination to be a game changer.
On the recent sailing aboard Celebrity Millennium out of Sint Maarten, two passengers tested positive for Covid-19. The ship was sailing with fully vaccinated crew and guests, and the two passengers were asymptomatic.
The Cruise Guy's Chiron, who was on board, said he was disappointed when passengers tested positive on day 6 of the cruise but that the safety protocols worked.
"Systems worked to the benefit of all aboard. The big change was passengers and crew were able to continue on with their cruise. Dinner, lounges, shows, casino ... were operating normally for the remaining 1.5 days," Chiron said.
Dr. Calvin Johnson, the chief medical officer for Celebrity, said neither he nor the crew are worried about cruising safely. "I think everyone really believes in -- because they were part of it -- the protocols that we've developed, the processes we put in place."
Celebrity Edge will be the first ship sailing from the US to put them to the test.
CNN's Natasha Chen, Nadia Kounang and Michael Nedelman contributed to this report.