ジェームズタウンの周辺には水没遺跡が無数にあった

アメリカ、ヴァージニア州のジェームズタウンは植民地時代初期から発展した都市です。歴史的に重要な意味を持っています。その海域で水中サーヴェイが行われました。

約７．８マイルほど島の周辺を１０日かけて調査したそうです。その結果、７０件ほどの水没遺跡が発見されました、そのうち重要な沈没船は２６件。海中の透明度が悪いので遺跡の状態を確認するにはダイビングする必要があります。沈没船のうち幾つかは１５０年前よりも新しいものだそうですが、かなり古い沈没船もあるそうです。

Waters around Jamestown reveal buried history
By the Associated Press
July 22, 2006
JAMESTOWN, Va. — Underwater archaeologists have discovered a trove of history in the waters around Jamestown.

Among their finds: 26 shipwrecks, including numerous barges approaching 100 feet in length as well as a 72-foot-long skipjack; and landings, wharves and piers, including one that may be linked to early 17th-century Virginia Gov. George Yeardley.

Stephen Bilicki has studied the Chesapeake Bay shoreline for nearly 20 years, and he’s still amazed at what the waters cloak. In just 10 days of work, for instance, Bilicki and his research team uncovered 70 potential archaeological sites around the 7.8-mile perimeter of the island.

“That’s the most shocking thing about this kind of work,” Bilicki says. “So many times we look around and think our past is gone. But a lot of it is preserved underwater.”

Based in Wachapreague on the Eastern Shore, the BSR Cultural Resource Specialists team began surveying along the water’s edge July 5. They worked with archaeologist Andrew Veech of Colonial National Historical Park and used a side-scan sonar device.

Then, for more than one week, they trolled back and forth along the shore searching for the distinctive acoustical signatures produced by manmade features.

This was the first comprehensive look at all the waterways adjacent to the 1,500-acre island, Veech told the Daily Press of Newport News.

Unlike some stretches of coastline Bilicki has surveyed in the past, the waters off the island were loaded with an unusual number of secrets.

“This is always fun work,” Bilicki says. “But usually it’s hours and hours of boredom followed by the excitement of–‘What’s this!”‘

Only Bilicki’s practiced eye enables him to decode the sometimes squiggly patterns of lines so quickly when they pop up on the computer screens.

“I’ve been looking at these things for years,” he says, describing the discovery of the skipjack a few days after the survey started. “So in most cases I can tell what something is just by looking at its acoustical signature.”

Still, even Bilicki’s keenly honed gaze can’t provide more than an estimate of the size of the wrecks on the bottom. That requires Veech and maritime studies graduate student Jodi Carpenter to don scuba gear, plunge over the side and take hands-on measurements in murky water.

“You can see light–but you can’t see anything. So you have to go slow, very slow–to avoid any spikes or entanglements,” Carpenter said. “It’s diving by feel, really–diving by Braille. But I’ve done so much of this kind of bad diving and so little of the other that I’d probably freak out if I ever saw something.”

One find emerges: a ferryboat hull 14 feet wide and 53 feet long.

The whole bottom of the boat seems to be intact. We’ve actually got some of the gunwales,” Bilicki says. “To us, that’s pretty exciting.”

By the time the study ended, the team intended to have taken basic measurements on every target.

“There are all kinds of visible and submerged things out here. Most of them are 150 years old or younger. But some of them are much, much older,” Veech says. “This will give us the baseline we need to start understanding what we’ve got.”

引用元：http://www.dailypress.com/news/local/virginia/dp-va--jamestownsburied0722jul22,0,7934786.story