United States Coast and Geodetic Survey

Coast Chart No. 4 Penobscot Bay Maine

Sounding Map Issued Oct.1880 (By Carlile P. Patterson Superintendent Verification by J. E. Hilgard assistant in charge of office) corrected in 1885

Coast chart No.105 from Penobscot bay to Kennebec Entrance

Sounding Map First publication 1873, corrected July 30 1897

Coast Chart No. 108 From Wells to Cape Ann

Approaches to Penobscot Bay

Mariners' Map, Corrected July 11 ,60, First edition January 1950