Amtrak Railroad Bridge encompasses the zone upstream of a line beginning at a point on shore at or near Lat. 39° 23.508’ N., Long. 76° 20.602’ W., then running 212° (True) to a point, at or near Lat. 39° 22.780’N., Long. 76° 21.195’ W., and downstream of a line beginning at a point, at or near Lat. 39° 22.798’N., Long. 76° 21.308’ W., then running 32° (True) to a point, at or near Lat. 39° 23.562’ N., Long. 76° 20.687’ W. Except as otherwise restricted, the speed limit for this area is 6 knots.