Miami: In a non-descript building in North Miami, two dozen dancers in bouncing yellow skirts are high kicking the can-can, aerialists are spinning perilously high from silk cords and frantic seamstresses are hemming outfits in a 20,000 square-foot costume shop. They are all part of a company that puts on more live productions a year than Broadway and London’s West End combined.

Royal Caribbean International’s cruise line directs 134 shows in 50 theatres on 26 ships around the world, including seven Broadway-originating shows, eight aqua shows, 18 ice shows and dozens of original musicals.

“We have a nightly audience of about 100,000. It is by scale a very, very large operation. Probably under one roof, the biggest in the world,” said Nick Weir, senior vice president of entertainment. “At any one time, there’s 1,500 to 1,800 cast members employed to make this all come to life.”

It takes two to four weeks for an army of dancers, singers and aerialists to learn a show before they’re dispatched to ports as far away as Australia and China.

On a recent afternoon, dancers roamed the halls in crop tops and buns. One stretched into a wide split on the floor. There are 14 dance studios, 15 rehearsal rooms, a recording studio, gymnasiums and auditorium. Exercise equipment lines some hallways. Nearby are living accommodations for 470 of the performers.

Often dismissed in the past as second-tier, cruise entertainment has evolved to a genre that Royal Caribbean says commands some of the best talent and technology around.

Several of the main characters in “Mama Mia” are from the Broadway version of the show. While New York theatre has struggled to turn profits with its small, intimate venues, fickle crowds and finite real estate, the cruise industry’s onboard audience is growing exponentially.