'Cruise Ship Drunk' and Ready to Rumble: Passengers Behaving Badly

ABC News' Jim DuBreuil and Eamon McNiff report:

While accidents  like the Costa Concordia disaster make headlines, far less serious cases of cruise ship chaos make it to YouTube. Videos of cruise ship passengers behaving badly, like the one below showing a brawl, get widely circulated on the site.

The video was taken aboard the Carnival Cruise Lines ship Dream in 2010. Stunned passenger Ian DelCastio captured the fight with his cell phone camera.

"All of a sudden were heard these screams. We turned around, and there's these two large parties that had just converged on the dance floor and started punching and kicking and yelling," he said. "It was mayhem. … It just exploded like a powder keg.

A Carnival  spokesman told "20/20? that the "ship's security and the cause of the fight had been investigated, which resulted in 10 guests disembarking in Mexico."  The cruise line also said it maintained a "high level of security through an onboard uniformed security force" and that Carnival had a "zero-tolerance-for-crime policy."

Typically, alcohol is to blame for fights, which are common aboard ships, said maritime safety and security consultant Randall Jacques.

"Passengers get extremely intoxicated on cruise ships in open waters," he said.

Passengers often get more inebriated than they would on dry land - a phenomenon that's inspired the expression "cruise ship drunk."

Jacques said cruise ship security crews can send rowdy passengers back to their rooms, but otherwise they're limited in what they can do.

Watch the full story on "20/20? Friday at 10 p.m. ET.