A passenger has gone overboard on the largest cruise ship in the world, Royal Carribean’s Wonder of the Seas, while off the coast of Cuba.

The unidentified guest went overboard late on Tuesday during the second day of a seven-day trip sailing from Port Canaveral in Florida to the Grand Cayman Islands, Royal Caribbean said.

“The ship’s crew immediately launched a search and rescue operation and is working closely with local authorities,” the company said.

Royal Caribbean said it was working with the US Coast Guard on the incident. However, a spokesperson for the South Florida branch of the US Coast Guard told Business Insider that the Cuban Border Guard is leading the search, because the incident occurred in Cuba’s territorial waters.

The incident was reported at around 9pm ET on Tuesday when an “Oscar! Oscar! Oscar!” call, which signifies an overboard emergency, was made, according to industry blog Cruise Hive.

The crew launched a three-hour search in the water using searchlights and smaller boats and the ship turned around to retrace its route.

Despite the search, the passenger has still not been found.

Passengers on board the 230,000-ton cruise ship Wonder of the Seas said that their original journey had already been diverted due to Hurricane Idalia.

The ship also made an emergency stop on the Cayman Islands on Wednesday, as a guest needed to disembark due to a medical emergency, Royal Caribbean told Cayman Compass.

The Wonder of the Seas is a 1,188 feet long ship, with 18 decks and enough space to accommodate 7,000 passengers and 2,300 crew members.

Royal Caribbean is planning to set sail an even larger ship, the Icon of the Seas, next year, breaking the Wonder’s record.

Earlier this month, another incident occurred on a Royal Caribbean cruise ship when an Indian woman died after allegedly jumping off the Spectrum of the Seas liner.

Reeta Sahani, 64, was declared missing in the middle of the night after her husband, Jakesh Sahani, 70, woke to find she wasn’t in their cabin. Her family confirmed later on that she had died.

Back in June, a 42-year-old woman had to be rescued after she fell off the Mariner of the Seas, another Royal Caribbean vessel. She went overboard 25 miles south of Punta Cana in the Dominican Republic.

Further incidents have also occurred on the cruise ships Carnival Magic, Carnival Elation and Emerald Princess. Only one of the people was successfully found and rescued.

It is estimated that 19 people go overboard on cruise ships each year, and only around four people are rescued, according to Insider.

The high amount of people falling off large ships has sparked debates surrounding cruise ships and whether they should be fitted with detection devices to alert crew if incidents like this happen.

“All cruise lines use a variety of measures to maintain a safe environment on board cruise ships, including physical barriers around the periphery of external decks and balconies, video surveillance systems in public areas, and trained crew members who can respond quickly to an unsafe situation or emergency,” a spokesperson for Cruise Lines International Association informed Insider.