Under several feet of water in the Connecticut River, a few miles upriver from Long Island Sound, archaeologists have found a "ballast pile," an oblong mound of stones that were once in a ship's hold for stability. The stones remained after the hull disintegrated.

The archaeologists wonder whether the wreck can be tied to a 200-year-old battle in which the British set fire to 25 ships, the largest maritime loss in the War of 1812.

Under gray skies off Watrous Point, a mile south of the town of Essex, archaeologists from the University of Connecticut and the Mashantucket Pequot Research Center stood waist-deep in the chilly river water recently removing hundreds of pounds of the ballast stone to reach remnants of the hull beneath. Waves from passing boats jostled the crews as they struggled to keep their footing....