The Potomac River encompasses all waters of the Potomac River and its tributaries westerly of a line from Point Lookout, at or near Lat. 38° 2.267'N., Long. 76° 19.300' W., then running 156° (True) to Smith Point, at or near Lat. 37° 53.367'N., Long. 76° 14.250' W.
Md. Code Regs. 08.18.21.01