The U.S. lifted the no sail order on Oct 30, but then implemented a framework for conditional sailing. But if they aren't going in to US ports then does the CDC have any jurisdictions?

Anyway - https://cruiseradio.net/celebrity-cruises-to-sail-from-st-maarten/
* vaccines required for adult guests and crew
* negative tests required for under 18 years old

"The first of the two itineraries being operated will call at Aruba, Barbados, and Curaçao, with the second itinerary visiting St. Lucia, Barbados, and Tortola."