The Board of Harbor Commissioners for Portland Harbor consists of five representatives charged with the responsibility of regulating navigation and commerce within Portland Harbor. The Commission’s authority results from various private and special laws passed by the Maine Legislature. The statutory jurisdiction of the Board of Harbor Commissioners encompasses all tidal waters within the municipal boundaries of Portland and South Portland, explicitly extending to and including Peaks Island, Great Diamond Island, Little Diamond Island, House Island, Cushing Island, Cliff Island and Jewell Island. 

The Commission includes two members appointed by the City of Portland, two members appointed by the City of South Portland, and one member appointed by the Governor representing the State of Maine.

The Harbor Master is appointed by and reports to the Board of Harbor Commissioners for Portland Harbor. The Harbor Master and Deputy Harbor Masters are tasked with the enforcement of the Rules & Regulations established by the Commission.