Famed Roman shipwreck reveals more secrets

Marine archaeologists report they have uncovered new secrets of an ancient Roman shipwreck famed for yielding an amazingly sophisticated astronomical calculator. An international survey team says the ship is twice as long as originally thought and contains many more calcified objects amid the ship's lost cargo that hint at new discoveries.

At the Archaeological Institute of America meeting Friday in Seattle, marine archaeologist Brendan Foley of the Woods Hole (Mass.) Oceanographic Institution, will report on the first survey of Greece's famed Antikythera island shipwreck since 1976. The ancient Roman shipwreck was lost off the Greek coast around 67 BC,filled with statues and the famed astronomical clock.

"The ship was huge for ancient times," Foley says. "Divers a century ago just couldn't conduct this kind of survey but we were surprised when we realized how big it was."

Completed in October by a small team of divers, the survey traversed the island and the wreck site, perched on a steep undersea slope some 150 to 230 feet deep in the Mediterranean Sea.

The October survey shows the ship was more than 160 feet long, twice as long as expected. Salvaged by the Greek navy and skin divers in 1901, its stern perched too deep for its original skin-diver discoverers to find.

The wreck is best known for yielding a bronze astronomical calculator, the "Antikythera Mechanism" widely seen as the most complex device known from antiquity, along with dozens of marble and bronze statues. The mechanism apparently used 37 gear wheels, a technology reinvented a millennium later, to create a lunar calendar and predict the motion of the planets, which was important knowledge for casting horoscopes and planning festivals in the superstitious ancient world.

A lead anchor recovered in a stowed position in the new survey shows that the ship likely sank unexpectedly when "a storm blew it against an underwater cliff," says marine archaeologist Theotokis Theodoulou of Greece's Ephorate (Department) of Underwater Antiquities. "It seems to have settled facing backwards with its stern (rear) at the deepest point," he says.

Scholars have long debated whether the ship held the plunder of a Roman general returning loot from Greece in the era when the Roman Republic was seizing the reins of the Mediterranean world, or merely luxury goods meant for the newly built villas of the Roman elite. The last survey of the shipwreck was led by undersea explorer Jacques Cousteau, whose documentary Diving for Roman Plunder chronicled that 1976 effort, which appears to have excavated the ship's kitchen.

The October survey team watched the 1970s documentary to help orient themselves to the wreck site. "They didn't have the diving technology that we now have to do a very efficient survey," Theodoulou says.

Along with vase-like amphora vessels, pottery shards and roof tiles, Foley says, the wreck also appears to have "dozens" of calcified objects resembling compacted boulders made out of hardened sand resting atop the amphorae on the sea bottom. Those boulders resemble the Antikythera mechanism before its recovery and restoration. In 2006, an X-ray tomography team reported that the mechanism contained at least 30 hand-cut bronze gears re-creating astronomical cycles useful in horoscopes and timing of the Olympic Games in the ancient world, the most elaborate mechanical device known from antiquity until the Middle Ages. "The (objects) may just be collections of bronze nails, but we won't know until someone takes a look at them," Foley says.

The survey effort, headed by Aggeliki Simossi of the Ephorate of Underwater Antiquities,will continue for the next two years. The international survey team will look in two different locales for ancient shipwrecks in that time, while Greek antiquities officials ponder further exploration. An amphora recovered from the wreck will also have its inner walls tested for DNA traces of the regular cargo, such as wine, once carried by the vessel.

Recovery of whatever cargo remains with the wreck, now covered in sand, presents a technically difficult, but not impossible, challenge for marine archaeologists.

"Obviously there are a lot of artifacts still down there, but we will need to be very careful about our next steps. This ship was not a normal one," Theodoulou says.