Preliminary chart of western end of Florida Reefs including Tortugas Keys.

Scale 1:200,000.
LC Civil War Maps (2nd ed.), 117.52
From its Report of the Superintendent of the Coast Survey, showing the progress of the survey during the year 1863 (Washington, Government Printing Office, 1864). Map 17.
"No. 17" is the upper left corner.
At head of title: U.S. Coast Survey, A. D. Bache, Supdt.
Description derived from published bibliography.
Available also through the Library of Congress web site as raster image.