  LNM19/72-- TUG REPORTED DUMPING 23 LARGE CONCRETE BLOCKS (23 FEET SQUARE, 2 FEET THICK) IN APPROX. LAT. 37-09.2N, LONG. 76-07.3W. 28 FEET REPORTED OVER BLOCKS. SMALL NUN BUOY, INT. ORANGE, ESTABLISHED. BLOCKS ARE REPORTED SCATTERED APPROX. 200-250 FEET