It all went down while the ship was moving, too.

By Raisa Bruner
February 07, 2017
Diving on cruise ship
Credit: Royal Caribbean; ROMAN KRUCHININ/AFP/Getty Images

Professional high diver Cesilie Carlton is fearless.

For proof, just check out this video of the champion U.S. athlete somersaulting from a 55-foot platform on a moving cruise ship, landing flawlessly in the swimming pool of the Royal Caribbean's Harmony of the Seas. Luckily, the ship—which is the largest cruise ship in the world—also boasts the world's deepest pool on a cruise ship, making it an ideal body of water for this kind of limit-pushing leap.

The video, taken by gymnast Sydney Brown, offers an unusual perspective of Carlton from above as she twists and turns into the water below. (Fifty-five feet converts to about five stories, for those keeping track.)

From her precise midair moves to her entrance into the water in exactly the right spot, this is not an activity for amateurs to try at home.

But for Carlton and her cohort—who perform acrobatics of this kind for cruise passengers regularly—the jump is just another day on the job. Brown and Carlton have shared many videos of their heart-stopping adventures, including vertigo-inducing cliff dives on the Italian coast into a narrow slice of the Mediterranean.

There's also this video, which shows just how high up that platform really is—and how precise the divers must be to hit their mark.

As for cruise passengers trying to get in some recreational thrills while aboard, the Harmony of the Seas is also home to the world's tallest slide at sea. It has a breathtaking 100-foot drop.