Shimonoseki Kaikyo to Kusayama Zaki

An uncommon reflection on America’s preparedness for war with Japan.

This detailed coastal map of Japan was published in 1945 by the U.S. Navy Hydrographic Office as an EMERGENCY REPRODUCTION OF B.A. CHART (upper left). The base image, covering a portion of Yamaguchi Prefecture’s southern coast, offers the earliest date as 1902, but subsequent updates were issued through early 1945. The use of a British Admiralty Chart by the U.S. Navy highlights close Allied strategic cooperation in the Pacific, in addition to America’s outdated cartography for certain parts of the theater.

The image notes depth soundings, navigational beacons, and coastal features. Topography is depicted in contour. Railways, temples, and other land-based facilities are also identified. The region was part of Japan’s Seto Sea, an inland body of water that was heavily industrialized and thus prey to American submarines and carrier-based aircraft.