Foster Branch and Joppatowne Channel encompass the area upstream of a line beginning at a point at or near Lat. 39° 23.667’ N., Long. 76° 20.915’ W., then running 90° (True) to a point, at or near Lat. 39° 23.667’ N., Long. 76° 20.765’ W., and running to the head of the branch. This area has a 6-knot speed limit all year.