The need to establish seafloor observatories has been important for decades. Multidisciplinary efforts aimed at establishing such observatories Beranzoli et al., 1998>are now culminating the ongoing Ocean Observatories Initiative <Copley, 2004>. This article reports on how the world's first seafloor geomagnetic observatory NWP (North-Western Pacific) is producing data that are compatible with those obtained by satellite ¿rsted and the existing geomagnetic observatory network. In particular, the article reports on the remarkable agreement between the satellite-predicted and actual secular variation, which ensures the accuracy of the geomagnetic measurements both in space and at the seafloor.