RELATED: If You’re Unvaccinated, You Now Can’t Go Here. More than half a dozen Royal Caribbean cruise passengers were left on the docks in Seattle, Washington, on Aug. 13 instead of being allowed to board a ship to Alaska, KIRO 7 News reported. All of the passengers left behind were unvaccinated, and said they had been told they only needed a negative COVID test to board the cruise ship. But according to Royal Caribbean guidelines released in late May, all guests 12 and older are required to present proof of COVID vaccination when boarding a cruise departing from Seattle. It’s not only Seattle: Royal Caribbean also requires passengers be vaccinated for cruises departing from Galveston, Texas. And this is also not the only cruise company mandating vaccinations for passengers in the country. According to Travel and Leisure magazine, passengers departing from most U.S. ports on Celebrity Cruises, Norwegian Cruise Line, Princess Cruises, Seabourn, UnCruise Adventures, and Victory Cruise Lines are required to be fully vaccinated before boarding.ae0fcc31ae342fd3a1346ebb1f342fcb “Let’s be honest—NO cruise line wants unvaccinated adults on their ships,” Alex Sharpe, president and CEO of Signature Travel Network, told The Washington Post in an email. “There is simply too much at stake.” The only major exception for many cruise lines in the U.S. is ships departing from Florida. Gov. Ron DeSantis has heavily pushed back against vaccine requirements over the past few months, even signing an executive order in May blocking any business or government entity from requiring proof of COVID vaccination in the state. As a result, Royal Caribbean is allowing unvaccinated passengers to board ships departing from Florida, but those who do not show proof of vaccination will be subject to extra costs in order to undergo regular COVID testing and maintain travel insurance. Unvaccinated guests—or those who do not show proof of vaccination—will be required to pay an additional $136 to $178 for third-party testing and provide proof of valid travel insurance with a minimum of $25,000 per person in medical expense coverage and a $50,000 coverage for emergency medical evacuation with no COVID-19 exclusions. RELATED: For more up-to-date information, sign up for our daily newsletter. For most cruises, unvaccinated passengers will not only be required to pay more, but will also likely be barred from vaccinated-only areas and events once on the ship. These passengers could also be prohibited from exiting the ship when it docks at certain ports, like at the port of San Juan, Puerto Rico. Meanwhile, one cruise company is fighting back against DeSantis’ order altogether. Norwegian Cruise Line Holdings will be the first cruise to require every person on board in Florida to be fully vaccinated despite the local policy, according to The Washington Post. On Aug. 9, a federal judge ruled in favor of the cruise operator, allowing it to bypass the ban on vaccine mandates for its first Florida-departing ship on Aug. 15. “We believe Florida’s prohibition is on the wrong side of federal law, public health, science and is not in the best interest of the welfare of our guests, crew, and the communities we visit, therefore, we have reluctantly turned to the courts for relief,” Norwegian Cruise said in a statement to CNBC, prior to the judge’s ruling. “Our policy of 100 percent vaccination of guests and crew is consistent and in place without issue in every port we sail from around the world except for Florida.” RELATED: If You’re Unvaccinated, You Could Soon Get Charged More for This Every Month.