The publication, in 1970, of a complete set of detailed bathymetric charts for the North Pacific Ocean (Chase et al., 1970) was a milestone for geologic investigations in the world's largest ocean basin. For the first time, investigators had a reasonably accurate, unified bathymetric base upon which to design experiments, test hypotheses, and compile scientific results. These charts, and their companion Bathymetric Atlas of the North Pacific Ocean (1973), have proved invaluable to our studies, over the last decade, of the Hawaiian-Emperor volcanic chain. The density and quality of data available to Chase and his colleagues varied widely; the western North Pacific was an area of minimal coverage. Since the charts of Chase et al. (1970) were first published, enough new bathymetric data have been collected in the area of the Emperor seamounts to warrant revision of the bathymetry (Plate 1, in pocket) of this unique volcanic feature.