Shipwreck Studies

by Claire Calcagno

Edgerton’s involvement with archaeology developed as an indirect consequence of his collaboration on an oceanographic project with Jacques-Yves Cousteau in 1953, at the ancient wreck site of the Grand Congloué in southern France. This was the first underwater archaeology project ever conducted by scuba-divers, a new technology that was opening up the seas to those interested in cultural as well as natural resources. Doc assisted Cousteau’s diving team with his strobe lights and sonar camera locator. Soon he began to focus on developing sonar instruments to scan and probe the sea bed for shipwreck sites. A few years later his underwater strobe lights were featured on the first submersible designed specifically for underwater archaeology, the Asherah.
Doc’s lights, cameras and sonar tools could be applied to archaeological search projects, surveys and for more detailed investigations of submerged sites, to record and document objects proud of seabed, and anomalies beneath sediments. Today sonar is the most commonly used remote sensing tool for detecting shipwrecks, artifacts and other cultural resources. Edgerton’s participation at dozens of underwater archaeology research projects around the world provides a valuable source of understanding into the symbiotic relationship between technology and archaeology in submerged environments.
Following his 1953 cruise, Edgerton had many opportunities on subsequent Calypso research expeditions to dive on ancient wrecks and observe Cousteau exploring the potentials of underwater archaeological research. Many of his archaeological connections over the following decades stemmed from his close working relationships established with Cousteau and his team of pioneering divers, oceanographic engineers and geologists. As word spread about Edgerton’s sonar ‘pinger’ that could perhaps trace buried objects, Edgerton began sending his students to deploy and test his prototype sub-bottom profiling instruments at underwater archaeological sites.

Field-testing his instruments at submerged archaeological sites was valuable to his own research as well as to the new sub-discipline of underwater archaeology. So Edgerton joined search and survey projects around the world, ranging from shipwrecks to sunken cities to harborworks; from the Late Bronze Age to the Age of Exploration up to the 20th century; from the Mediterranean to the South Pacific. He was ever ready to volunteer to join a team, and worked with whatever means were available for him to field-test his equipment. He often brought along his sonar equipment at his own expense; he also secured funding and publication opportunities for his archaeologist colleagues (particularly through his connections at National Geographic Society).

Edgerton first used side scan sonar successfully to locate a modern wreck site off the Massachusetts coast, the Vineyard Lightship, in 1963. The first side scan sonar search to positively identify an ancient shipwreck (off the coast of Turkey in 1967) was conducted with a side scan sonar of his design, by a former MIT student of his, Martin Klein (MIT ’62) near the site of Yalikavak in SW Turkey. Only a couple of months later, using both a side scan sonar and a sub-bottom profiler, Edgerton and his team assisted in locating the Mary Rose (King Henry VIII’s flagship) which sank in 1545. Edgerton used his mud penetrator to search for the ancient harbor city of Helike, lost to an earthquake in the fourth century BCE – although his searches did not prove successful. Nevertheless Edgerton’s field and lab notes indicate that although specific targets might not always have been identified, nonetheless the sheer volume of sonar testing data retrieved, made his trips a success in his eyes.
Over the years Edgerton presented his fieldwork results to the broader archaeological community, encouraging the use of sonar surveying instruments, through conference talks and articles published in specialized journals in their field. The archaeological community has clearly acknowledged his contributions: in 1989, shortly before his death, Edgerton was presented with the “Pomerance Medal for Scientific Achievements in Archaeology,” issued by the Archaeological Institute of America.
Edgerton offered archaeologists new ways to see with sound waves through water and beneath the sediments. While he modestly referred to his archaeological collaborations as “creative mischief”, he acknowledged his debt to archaeological fieldwork for his own career in a telling fashion. For the frontispiece of his collection of sonargraphs reflecting a career of work, Sonar Images, published in 1986, he chose to illustrate an artifact retrieved from that Grand Congloué wreck-site he had first explored with Cousteau in 1953. The artifact, a Roman sounding lead, represents the earliest known instrument used to measure sea depth and provide diagnostic information about the sea bottom sediments — indeed, an ancient analog to Edgerton’s own instruments.

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