Fig. 3. Global source "deck" makeup of COADS Release 1 (CMR) for 1854-1949, grouped according to roughly national categories, plus Historical Sea Surface Temperature (HSST) Project data. Categories were defined in Table 3 of Woodruff (1990), except the additional category "Japanese" (Kobe Collection) comprises decks 118-119 (almost exclusively deck 118 during this period). Note the virtual absence of U.S. data prior to 1941, and the predominance of Japanese data during 1940-41, of U.S. data during 1942-45, and of Netherlands data prior to 1880 (it is undocumented whether the Dutch and some other early decks might actually be international compilations).