The bathymetric contours are derived from those contained within the GEBCO Digital Atlas, published by the BODC on bahalf of IOC and IHO (2003) (http://www.gebco.net)
Shoreline data is derived from: United States. National Imagery and Mapping Agency. "Vector Map Level 0 (VMAP0)." Bethesda, MD: Denver, CO: The Agency; USGS Information Services, 1997.