I saw commercial side scan sonar imagery in 1972 that was quite impressive. Sure, it's a lot better now but the early towed array SSS systems were not as bad as you seem to imagine Georger. Motion compensation, digital signal processing and image processing algorithms have made today's SSS images look like monochrome photographs but the early models without all that did a decent job.
Look at the results achieved using 1960s commercial SSS: During these developmental years, Doc (Edgerton) and Klein participated in many dramatic demonstrations of the search abilities of side scan sonar. In 1967, Klein assisted pioneer underwater archaeologist George F. Bass in the discovery of a 2,000-year-old Roman shipwreck off southwest Turkey—the first ancient shipwreck found using remote sensing. Later in 1967, Doc helped locate the 16th century HMS Mary Rose—now a major archaeological exhibit in Portsmouth, England. Both of these discoveries were the first significant finds of historical vessels made with side scan sonar.
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