Green Bay−Lake Michigan line means a line com- mencing at the northwest side of the Northport dock where it joins the shoreline in section 33, T33N, R29E; then running northeast- erly to the range light (signal light) on Plum island; then running along the north and west shore of Plum island to the U.S. coast guard station; then running northerly to the southwesterly point on Shellswick dock, which is located on Lobdell’s point on Washing- ton island; then running along Shellswick dock to the shoreline of Lobdell’s point; then running along the west shore of Washington island to Boyer’s Bluff light; then running north to its terminus at the Wisconsin−Michigan boundary line.