Underwater Archaeology


     In September 1980, the archaeologists began work. A remote sensing survey was the first research on the wreck site. Its purpose was to find out all that they could about the ship before the excavation began. Archaeologists used a magnetometer, side-scan sonar and subbottom profiler. The side-scan sonar gave the most useful information. It produced a clear picture of the sea floor using sound rather than light. This image showed the ship's outline, a cannon, and the holes where the finders used a dredge to dig at the site.


     The side-scan record served as a map for planning excavations. Archaeologists marked a line down the center of the ship, and then laid 10-foot squares off this line. Spikes marked the corners of the squares. Two underwater archaeologists directed the excavation, and trained divers worked with them. They mapped and excavated what they found within these square units.


     El Nuevo Constante lay in about 18 feet of water. However, divers could not see the wreck because of mud. The liquid mud formed a thick soup extending 2 or 3 feet above the sea bottom. As a result, the archaeologists excavated and mapped by touch. Divers used surface-supplied air and had radio contact with the diving boat.


Side-scan sonar image.



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