GEORGETOWN, S.C. ˜ Two miles off a deserted beach, the research vessel C-Hawk, its course plotted by satellite navigation signals, makes a 180-degree turn and heads back the way it came. One mile and it will turn again, recording the ocean floor's magnetic profile as systematically as if it were a tractor plowing a field. In the past month, the South Carolina Institute of Archaeology and Anthropology research vessel has surveyed 6 square miles of the ocean bottom outside the mouth of Winyah Bay, searching for the 500-year old flagship of the expedition that established America's first colony ˜ on the Georgia coast."If the Spanish had this kind of navigation gear in the 16th century, we probably wouldn't be out here looking for this ship now," grins archaeologist Jim Spirek, looking up from the computer screen in the cabin of the C-Hawk.

In August 1526, as Lucas Vazquez de Ayllon's fleet of six ships plied these waters, depths were determined by dangling a lead weight overboard at the end of a line. The method had its limitations. Ayllon's flagship ran aground ˜ and the first European effort to colonize the mainland of North America began to go horribly awry.

American history brims with accounts of Jamestown, Plymouth Rock and Sir Walter Raleigh's Lost Colony of Roanoke. But there isn't much said about Ayllon's effort to establish a colony of 600 people nearly a century earlier.

One reason is that the colony, San Miguel de Gualdape, was an abject failure. The other is that no trace has ever been found of Ayllon's initial landing on the Carolina coast or the short-lived colony he established later in Georgia.