Underwater archaeologist Franck Goddio and his Institut Européen d’Archéologie Sous-Marine (IEASM) team have discovered the remains of a 35-meter-long ancient Egyptian pleasure boat, known as a thalamagos, in the submerged Portus Magnus off Alexandria’s harbor. The 28-meter preserved timbers, found seven meters underwater and buried under sediment, represent the first physical evidence of such vessels, previously known only from ancient texts like Strabo's Geography and the Nile mosaic at Palestrina. The ship, built in Alexandria and propelled by oars, features a central pavilion and Greek graffiti from the 1st century C.E., and may have sunk around 50 C.E. during the destruction of the temple of Isis on Antirhodos Island.
This discovery matters because it provides tangible archaeological evidence of a type of ceremonial vessel described in classical literature, potentially linked to the rituals of the goddess Isis and the reign of Cleopatra. The Portus Magnus site, which sank due to natural disasters over 1,200 years ago, has yielded temples, statues, and coins, and this find offers new insights into the religious and political life of Ptolemaic Egypt. The research underscores how underwater archaeology continues to recover lost chapters of ancient history, with implications for understanding the connections between Hellenistic culture, Egyptian religion, and Roman-era Alexandria.