(a) The use, administration, and navigation of the canal and canal grounds shall be under the direction of the District Engineer, Engineer Department at Large, in charge of the locality, and his authorized agents. The term "canal" shall include all of the natural waters of the St. Marys River on the U.S. side of the International Boundary and all of the canalized waterway and the locks therein between the western or upstream limit, which is a north and south line tangent to the west end of the Northwest Pier, and the eastern or downstream limit, which is a north and south line tangent to the northeast corner of the old Fort Brady Reservation, the distance between limits being 1.9 miles. The term "canal grounds" shall include all of the United States part and other lands, piers, buildings, water level regulation works, hydroelectric power plant, and other appurtenances acquired or constructed for the channel improvement and use of the waterway. Note: Rules and regulations governing the movements of vessels and rafts in St. Marys River from Point Iroquois, on Lake Superior, to Point Detour, on Lake Huron, prescribed by the U.S. Coast Guard pursuant to 33 U.S.C. 475 , are contained in part 92 of this title.