Since 1973, four Japanese ore carriers have made regular surface measurements of temperature and salinity, every 60 nautical miles, between New Caledonia and Japan. They have followed two different routes; a western one from Noumea (22°16′S, 166°27′E) in New-Caledonia to Miyazu, Wakasa Bay (35°32′N, 135°12′E) in Japan crossing the equator at 150°E, and an eastern one to Hachinohe (40°32′N, 141°32′E) in Japan crossing the equator at 160°E. On each of these routes, the seasonal variations of navifacial temperature and salinity have been described in connection with the meteorology. Long-term variations have also been revealed. Finally, a description of the surface water masses has been attempted.