The crew of a half-sized replica of the Dover Bronze Age boat had to abort the vessel's maiden voyage when it failed to stay afloat as it entered the water.
The vessel, Boat 1550 BC, was lowered into Dover Harbour, Kent, at 1pm today but immediately began to take on water, a spokeswoman for Canterbury Christ Church University, which is helping to co-ordinate the project, said.
The project, in which a team of specialist archaeologists built the vessel over three months on the Roman Lawns at Dover Museum, is supported by the European Union and brings together seven partners from Britain, France and Belgium.
The replica was built just metres away from the underpass where the original 3,500-year-old Bronze Age Boat was discovered in 1992, the spokeswoman said.
She added: "It didn't go to plan so we had a bit of a naming ceremony instead.
"They had the boat carefully placed in a crane hammock but it filled up straight away. No-one was in it."
The spokeswoman said the boat would be moved to a trailer on the seafront so visitors could take a look and speak to the archaeologists.
She added: "They are going to patch it up and try to do this again. It's a bit disappointing for them but they were so behind schedule they could not do their test run."
The construction and launch of the boat was the first stage of a three-year programme of events that make up the project.
The vessel will be taken to France, where it will form the centrepiece of a major multilingual, international exhibition Beyond the Horizon: Societies of the Channel and North Sea 3,500 years ago, which opens in Boulogne-sur-Mer on June 30, before moving to Belgium in December and returning to Dover in July next year, the spokeswoman said.
Educational activities will also aim to increase awareness of the common cultural heritage in France, the UK and Belgium, she said.