FERRISBURGH, Vt. (AP) - A Revolutionary War gunboat that was part of a fleet commanded by Benedict Arnold before he turned traitor has been found sitting upright at the bottom of Lake Champlain, astonishingly well-preserved by the cold, deep water for the past 220 years.
The wooden vessel, which was either abandoned or scuttled by retreating American forces after a losing 1776 battle against the British, was found by a team scanning the lake for wrecks before they become encrusted by a new invader, the tiny zebra mussel.
The 54-foot vessel, whose name is not yet known, is largely intact, its mast still standing over 50 feet high and its large bow cannon still in place, said Art Cohn, director of the Lake Champlain Maritime Museum.
"This could prove to be the most significant maritime discovery in American history in the last half-century," said Philip Lundeberg, curator emeritus of naval history at the Smithsonian Institution's American History Museum. "The apparently excellent condition of the gunboat is highly unusual for an artifact this old and is one of the reasons the discovery is so significant."
No decision has been made yet on whether to raise the ship. Its exact location and depth in the 115-mile-long lake between New York and Vermont were not released.
The lake's cold water, up to 409 feet deep, is credited with preserving a number of wrecks that have been found there in recent years.
Only four of the 15 boats commanded by Arnold survived the Battle of Valcour Island on the lake and its aftermath in October 1776. One other member of the fleet, the Philadelphia, was raised in 1935 and now sits in the Smithsonian in Washington.
Cohn, lake historian Peter Barranco and others were scanning a section of the lake in early June when a long-sought image appeared on the sonar screen.
There was a mast, intact but for a small piece broken off the top. There was a nearly two-ton bow gun. And it was a nearly exact copy of the Philadelphia.
Cohn said that when he went down on the first dive to the ship, "there was a voice screaming in my head, `Oh my God, this is the gunboat! Benedict Arnold probably walked on this deck!"'
While the Philadelphia was damaged and sunk during the battle, this vessel apparently escaped.
It may have been hit during the engagement and then allowed to sink after the crew stopped bailing. Or the Americans may have punched a hole in it. The boat is sitting in mud, which obscures any possible damage to the hull.
Although the tiny fleet was defeated, it slowed the British advance from Canada. When the British finally made it to the Hudson Valley south of the lake the following spring, the Americans had been able to amass enough troops to win what many historians have called the decisive battles of the war.
Three years later, in 1780, newly married and strapped for cash to maintain an extravagant lifestyle, Arnold began providing information to the British and eventually joined British forces as a brigadier general.
This was the last of the 11 missing ships from Arnold's fleet to be found.
"There was never any doubt in my mind that it was out there," Barranco said. "History had told us so."
A team headed by Cohn has been using sonar to scan the depths of the lake for artifacts, including ships sunk in storms and battles in the 18th and 19th centuries. Their work has been lent new urgency by exploding populations of zebra mussels, a species that has wreaked havoc in North American waters since it arrived in the bilge water of European ships a decade ago.
Cohn said the strategy of the Lake Champlain Maritime Museum, founded in 1986, has been to leave wrecks in the cold preserving water. But the threat of zebra mussels may change that approach.
In the meantime, the team won't say exactly where the ship is.
"It should not become a thing for souvenir hunters," said Sen. Patrick Leahy, D-Vt. "It should not become something that everybody goes down to take a piece of."