A British cruise ship entertainer, 20, is missing after going overboard on Christmas Day.
Rescuers have been searching through the night for Arron Hough after the alarm was raised when he did not report for work on the Harmony of the Seas.
The vessel, run by Royal Caribbean, was 267 miles north-west of Aguadilla, Puerto Rico, at the time and en route to Philipsburg, St Maarten.
The United States Coast Guard said it had deployed a Clearwater HC-130 Hercules airplane crew and the Coast Guard Cutter Resolute in the search.
A spokesman for Royal Caribbean said: "We are saddened to report that after a review of the ship's closed-circuit camera footage, he was observed entering an area on Deck 5 at around 4am and was not seen again.
"Local authorities were notified and a ship-wide search for the crew member was conducted.
"Our care team is providing support to the family and friends of our colleague, and our thoughts and prayers are with them during this difficult time."
In July, talent agency Russell Smith Associates tweeted that Mr Hough would be joining the cast of Grease The Musical on Harmony of the Seas.
The London-based agency said: "Our thoughts are with all of his friends and family and we hope for him to be found very soon."
The Royal Caribbean website says the Harmony of the Seas won the title of largest cruise ship in the world in 2016.
The ship cost one billion US dollars (£695 million), can carry 6,780 guests and 2,100 crew, and took more than two-and-a-half years to construct.
The website says it is the first ship to feature the Broadway hit musical Grease as part of its entertainment programme.
Harmony Of The Seas departed Fort Lauderdale, Florida, on Sunday for a seven-night cruise including calls at Philipsburg, St Maarten, San Juan, Puerto Rico and Labadee, Haiti.
