With the formation of the Submerged Cultural Resources Unit in 1980, a decision was made by the National Park Service to use Isle Royale National Park as the focus of a prototype research program to inventory maritime archaeological sites. The phase of management-oriented archaeological research, which emphasizes documentation and evaluation of known sites, was considered the priority. This report is the result of the Isle Royale underwater research effort, and it includes a series of recommendations for future protection and interpretation of underwater archaeological sites that should have application to many other areas of the National Park System. In addition to this report, a considerable quantity of videotape footage and photographs has been organized into a format that permits easy accessibility to interested managers or researchers. -- AATA