It looks like the rib cage of a large marine mammal, whose bones turned black as it was fossilised. The wreck was discovered in May during a dig in Antibes, on the French Riviera, prior to construction of a car park on the site of the Roman port of Antipolis.
Archaeologists have gradually uncovered a 15-metre length of hull and structural timbers, in "exceptional" condition, according to Giulia Boetto, a specialist in ship design at Aix-Marseille University who is involved in the dig. Saw and adze marks are still visible on the wood. Luckily the ground in which it was found is always waterlogged so this prevented the timber from rotting and decomposing.
Sprinklers have kept the hull and its structure moist since its discovery. "Otherwise, in just a few weeks we would lose everything," says Isabelle Daveau, an archaeologist at France's Rescue Archaeology Research Institute (Inrap) and head of the project.
The ship – a merchant vessel from the imperial period – was probably about 22 metres long and six or seven metres across. It is thought to have sunk in the second or third century in the port at Antipolis. "It has a typical Graeco-Roman flat-bottomed design," Boetto says, with a hold three metres deep and a square sail to drive it, suspended from a mast, which has not been found.
The archaeologists have made some touching discoveries, including a little 15-centimetre brush that must have been dropped by a shipwright busy caulking the hull. It most likely fell through a gap between the floor of the hold and the outer shell, only to be discovered 19 centuries later.