Regret to inform that:
12285_18 POTOMAC RIVER ST CLEMENTS BAY MD INSET 7.png
Of course it's corrupt -- it's only 45 miles from Washington!
Actually, there is something strange about the original .bsb file. Maybe it's just a text table without any geographic data. I tried to read it with three programs and none would make any sense out of it. I'll post a message here if I get it working.