In a video recently obtained by KPRC 2, a young boy is seen climbing over the side of the Carnival Liberty and hanging by a rail before climbing back up and being helped onto the ship while some nearby passengers laugh.
While the unidentified boy came away unscathed, the incident could have potentially resulted in tragedy.
"This literally made my heart beat super fast and made me nervous. Kids just don't understand that they are not invincible," ship passenger Buffy Halbrooks Augustine told KPRC 2."He thought he was having fun and never considered the possibilities."
Another passenger aboard the Carnival Liberty, Marcus K. told KPRC 2 the act was "incredibly dangerous."
"He would have been sucked under immediately," he added.
The incident occurred Nov. 19 cruise sailing out of Galveston, Texas.
In a statement to KPRC 2, Carnival said it's investigating the video.
"We recently became aware of the video and are investigating. We strongly condemn any such behavior by our guests that puts themselves or others at risk."
The disturbing incident comes just months after a 33-year-old woman fell overboard on the Carnival Liberty, prompting a rescue effort by the U.S. Coast Guard that was eventually called off days later.