In searching the Internet for sites dealing with the Atocha and Mel Fisher, I found some additional locations that dealt with the larger topic of treasure hunting. These sites could add additional technical information about how underwater archaeology is conducted. The library's book catalog, and periodical indexes, should turn up books and articles on this broader topic.
HRD "Historical Research and Development, Inc. (HRD) is a company engaged in the historical research, archaeology, and marine excavations of America's Colonial period shipwrecks. A privately held Florida corporation, HRD was founded in 1988." Some of its officers worked with Mel Fisher on the Atocha site.