Naumachiae were usually held on lakes or man-made ponds. The first recorded naumachia was staged by Julius Caesar in 46 BC, on a pool excavated in the Campus Martius in Rome.
From that day on, the naumachia became a popular event. Successive Roman Emperors were to host ever larger and more extravagant events. Claudius staged a naumachia on the Fucine Lake in AD 52, in which a hundred galleys and 19,000 convicts re-enacted a battle between Rhodes and Sicily, whilst spectators watched from the surrounding hills.
The Romans brought all of their engineering and showbiz skill to bear when creating effects for the naumachia. Man-made islands would rise from the waters, whilst animals swam alongside the embattled ships. They also attempted to incorporate mythical elements, with the use of women dressed as nymphs or mermaids.
Those who fought in naumachia were known as naumachiarii, and most were condemned men or prisoners of war. They were motivated by a combination of inducement, such as the promise of freedom if they fought well ( or survived ), and the threat of a hideous death if they didn't fight.
Naumachiae in the Colosseum
Whether or not the colosseum was used to stage naumachiae is open to debate. The arena sand rested upon wooden boards, which covered a 6 metre deep basement. It was from this basement that animals, men and scenery were hoisted up to the arena by lifts. It is conceivable that the Romans could have removed the sand and boards before flooding the basement to put on a naumachia. Such a feat was certainly not beyond the capabilities of Roman engineers.
But it raises problems, because naumachiae were usually incorporated as a one of several events at the games. Thus, a naumachia might take place, followed by gladiatorial combats. For this to occur, the arena would have had to cleared, flooded, drained and rebuilt, all within the space of several days. It would have entailed the use of vast amounts of manpower and the relocation of many animals, props etc, which were usually kept in the arena basement.
If the arena was used to host naumachia, then the scene would most likely have been chaotic and hellish in the extreme. The relatively small space would have made any ' naval manouevers' virtually impossible, and a dense mass of men slaughtering each other on boats locked together, as in a log-jam, would have been the most likely result.
Sources:
Colosseum, Rome's Arena of Death, Peter Connolly, BBC Books, 2003
