The Website for GEBCO, the most comprehensive Bathymetric Chart of the world from UNESCO, and the International Hydrographic Organisation (IHO), now includes a gazetteer of undersea feature names. The downloadable Excel spreadsheet gives names and geographic data on undersea canyons, troughs, seamounts, banks, rises, channels, fracture zones, etc. The .pdf file gives the guidelines used in assigning undersea feature names, definitions of terms, and contact information for members of the GEBCO Sub-Committee on Undersea Feature Names and the Working Group on Maritime and Undersea Features of the United Nations Group of Experts on Geographical Names (UNGEGN). The 38 page text is in English and French.