A dugout canoe that was nearly chopped into firewood has turned out to be the oldest boat found off the British coast.
The 16ft vessel, carved from the trunk of an oak or elm tree, was used about 1,200 years ago by the Anglo-Saxons, possibly as a ferry close to the Suffolk coast where it was found.
Archaeologists believe the boat, which was discovered when it was dredged from a depth of 40ft by a trawler close to Southwold, is the only example of its kind dating back to the Anglo-Saxon era.
The vessel, which was probably fitted with stabilising outriggers, has spent the past four years submerged in a muddy lagoon at Covehithe, near Southwold, while conservationists worked on it.
Eventually, the necessary funding for the radio-carbon dating came from British Energy, the owner of the Sizewell nuclear power station close to the area where the boat was found. The process dated the vessel to between AD775 and AD845, before the reign of Alfred the Great and during raids along the East Anglian coast by the Vikings.
Stuart Bacon, the director of the Suffolk Underwater Studies Unit, said: "We have established that it is the oldest vessel ever found in the sea around the UK.
"It is very fortunate that the canoe was completely covered by a layer of protective silt and mud for most of the time when it was on the seabed – otherwise it would have been completely eaten away by worm."
The boat was found in 1998 by a fisherman, Rodney Collett, who had planned to cut the wooden hulk into logs but decided first to consult Mr Bacon, who realised its significance.
The boat was made by hollowing out the tree with a bladed carving tool called an adze and was probably used on the Norfolk and Suffolk Broads, which at the time would have stretched to the coastal spot where it was found.
The craft has now been moved to a marine laboratory for years of conservation work before it is transferred to a museum.