Ridley Scott‘s “Gladiator II” is full of a memorable action scenes, from a bloody showdown featuring CGI baboons to Paul Mescal outsmarting a charging rhino in the Roman Colosseum. But one sequence that is sure to leave audiences with the most questions is a rather insane set piece in which the Colosseum is filled with water and sharks. The gladiators enter the arena on a boat as a mock sea battle is staged, much to the delight of the sadistic emperors Geta (Joseph Quinn) and Caracalla (Fred Hechinger).

But did the Colosseum actually get flooded with water and sharks in real life? It’s a question that’s warranted given Scott often plays fast and loose with history. For instance, “Gladiator II” features a character reading a newspaper 1,200 years before the invention of the printing press. And don’t get us started on Scott’s “Napoleon,” which was so littered with historical inaccuracies that French historians slammed the director and said he was “spitting in the face of French people.”

When it comes to the Colosseum sea battle in “Gladiator II,” Scott is surprisingly not deviating too far from history. A form of ancient Roman theater was called “naumachia,” in which sea battles were staged for entertainment either in basins where battles had already taken plane or in flooded amphitheaters. Convicts or prisoners of war would face off against soldiers until one side was the winner.

The first naumachia on record dates back to 46 B.C. and was authorized by Julius Caesar, and some of them were eventually staged in the Colosseum. Roman emperor Domitian is believed to have put on a sea battle in the Colosseum in 85 AD, for instance. The “Gladiator II” naumachia raises the stakes by having sharks, although that is unlikely to have happened in real life.

Chris Epplett, a Greek and Roman history professor at the University of Lethbridge, told Vulture that he is not aware of sharks ever being put inside the Colosseum, although “there was a period when they could have flooded the floor of the arena. There was basically a period of, I think, 10 to 20 years before they put the full basement in, when they could have flooded the floor and had exhibitions with marine animals and that sort of thing.”

Speaking to Variety at the “Alien: Romulus” premiere earlier this year, Scott wisecracked about the sharks by saying: “That’s easy. Someone said, ‘How do you get sharks in the Colosseum?’ I said, ‘You can build the Colosseum — how stupid are you?’ I mean, you catch a few sharks and lob them in. They could do that.”

“Gladiator II” is now playing in theaters nationwide from Paramount Pictures.