Roman emperor Caligula famously led "orgy ships" that became the stuff of legends. Now, researchers are scouring the volcanic Lake Nemi in Italy in hopes of finding the emperor's last lost pleasure boat.

Gaius Julius Caesar Augustus Germanicus or "Caligula" was the third emperor of the Roman Empire ruling from 37 to 41 A.D. The eccentric ruler often dressed as a woman and called himself a god, but also built a reputation of being particularly sadistic and psychopatic, according to a report from Telegraph.

One of the mysteries attached to Caligula is the location of his missing party boat. The emperor had huge luxurious barges built so he could take pleasure cruises around Lake Nemi. Legends describe these boats as floating palaces with heating, plumbing and ornate fittings of gold, marble and mosaic. Rich purple silk sails billowed in the wind. Inside the massive ships, orgies were said to occur.

Two such ships had already been found in 1928 and 1932, but it's believed that a third barge exists, yet to be found.

In hopes of solving this mystery, Italy officials are leading an expedition to the depths of Lake Nemi. A report from Seeker revealed that the search will include researchers from the Environmental Protection Agency of Calabria, Carabinieri divers of Rome, Port authorities of Fiumicino, Rome, and ISPRA, the Italian National Institute for Environmental Protection and Research.

Local fishermen spoke of an area in the lake where they would throw their nets and find themselves hauling ancient Roman artifacts.

"We know from documents from the 15th century that one of the boats went down in an area of the lake different to where the other two were found during the Fascist era," local mayor Alberto Bertucci told The Telegraph.

Extravagant artifacts are expected to be recovered with the shipwreck, should the researchers find them.

Last month, the team observed the 100-foot-deep lake using side-scan sonar and sub-bottom profiling, which can detect objects buried up to 9 feet under the lake bed. The two-week survey yielded enough data for analysis until the end of June.

"We have already noticed some anomalies," Luigi Dattola of the Environmental Protection Agency of Calabria said in an interview with Seeker. "They will be investigated by the Carabinieri divers in the next days."