A Russian nuclear-powered submarine sinks in the icy water of the Bering Sea; an American trawler goes under without warning southwest of Alaska; the "Edmund Fitzgerald disappears on Lake Superior--these case studies and many more are unearthed in this investigation of underwater forensics. The resources of technology, science, maritime legend, and history are incorporated to uncover the origins of unexplained sea disappearances and shipwrecks and to find causes as straightforward as human error or as complicated as outright criminality. Also described are the eye-opening conclusions deduced from information retrieved 20,000 feet below sea level with new technology.