A Short Introduction: James Steffes (ENC Ret.) wrote a book about a swift boat (PCF-19) that was sunk (Hostile Fire) off the Vietnam coast just south of the DMZ. "SWIFT BOAT DOWN". It includes locating the boat & recovery of the bodies of some crew members. The USS Acme (MSO-508) used her VDS sonar to locate it. I was the Motor Whaleboat Coxswain during the recovery. Navy Seals dived on the boat to recover bodies, equipment & documents.