Chart of Fishers Island Sound and New London harbor

The back of the Custom House Maritime Museum faces New London harbor and stood at water's edge before the railroad came through.  From its second floor windows most of the maritime activities of New London are visible: ferries to three destinations, submarines leaving or returning to the Submarine Base, submarines under construction across the Thames in Groton, the Coast Guard training bark Eagle and other USCG cutters, as well as remnants from the city's maritime past. The library's book collection is complemented by maps and charts such as this U.S. Coast and Geodetic Survey chart of Fishers Island Sound and the Thames, displayed in 2016 for close inspection under glass.