Underwater archaeologists announced on Monday they had discovered the 2,000-year-old wreck of an ancient Egyptian pleasure boat off the coast of Alexandria.
Divers found the vessel's hull, which was more than 35 metres (115 feet) long and some seven metres wide, submerged in the port of the island of Antirhodos, the European Institute for Underwater Archaeology (IEASM) said in a statement.
There was Greek graffiti on the vessel that "could date from the first half of the first century AD" and "supports the hypothesis that the ship was built in Alexandria".
The boat "would have had a luxuriously decorated cabin and appears to have been propelled solely by oars," the Alexandria-based institute added.
Alexander the Great founded the city of Alexandria in 331 BC. A series of earthquakes and tidal waves that struck its coast submerged the island of Antirhodos, which was discovered in 1996.
Over the years, divers have recovered statues, coins and other treasures there, with some on display at the Greco-Roman Museum in Alexandria.
IEASM director Franck Goddio recently published a report on Antirhodos and its Temple of Isis, based on underwater exploration carried out since the 1990s.
Future research on the recently discovered wreck "promises to be a fascinating journey into the life, religion, wealth and waterway pleasures of ancient Roman Egypt," the institute said.
Alexandria is home to ancient ruins and historic treasures, but Egypt's second-largest city is especially vulnerable to climate change and rising sea levels, sinking by more than three millimetres every year.
Even in the United Nations' best-case scenario, a third of Alexandria will be underwater or uninhabitable by 2050.