Starting in 80 CE, residents of Rome and visitors from across the Roman Empire would fill the stands of the Colosseum to see gladiators duel, animals fight and chariots race around the arena. And for the grand finale, water poured into the arena basin, submerging the stage for the greatest spectacle of all: staged naval battles. Janelle Peters details the history of these mock maritime encounters. [Directed by Brett Underhill, narrated by Bethany Cutmore-Scott].