Excavating 300-year-old French ship.

Excavation of famed French explorer Rene-Robert Cavelier, Sieur de La Salle's ship, the Belle, is under way off the Texas coast. The shipwreck site is the first in the hemisphere to use a cofferdam -- a watertight structure designed to keep liquid out of an enclosed area -- in deep waters. Once it was complete, seawater was pumped out so archaeologists could excavate on dry land. The cofferdam was essential for excavation due to the silty waters of the Gulf of Mexico, where visibility is less than a foot. Any movement including that required by excavation, would make visibility impossible.

The Belle is the oldest French shipwreck ever discovered in the Americas. ran into a storm and sank in 1686. La Salle is the French explorer who claimed the Mississippi River and its drainage for France, including much of the area that now is Texas.

First found in the summer of 1995 off the Texas coast by a team of researchers led by marine archaeologist Barto Arnold of the Texas Historical Commission (THC), the find represents one of the most significant underwater archaeological discoveries ever made n North America. "The shipwreck is extremely intact for a 3CO year-old vessel; we believe that the unique nature of the sediment found on the bay's floor helped to preserve the ship's organic material," indicates Curtis Tunnel THC executive director.

In July 1995, THC's marine...