Salem Maritime National Historical Park Redesignation and Boundary Study Act This bill redesignates the Salem Maritime National Historic Site in Massachusetts as the Salem Maritime National Historical Park and directs the Department of the Interior to conduct a boundary study and report to Congress. Such study shall be to evaluate the suitability and feasibility of including in the National Park System, as part of the Salem Maritime National Historical Park, sites and resources in the study area associated with its maritime history, coastal defenses, and military history.