Australian Hydrographic Service has over 400 paper charts plus electronic and raster charts. An interactive browser identifies charted areas within the Australian region.
National Geophysical Data Center is the official distribution point for National Ocean Service bathymetric maps, bathymetric/fishing maps, regional maps, geophysical maps, and preliminary maps. NGDC also has an interactive map (ArcIMS) graphic selection page, and previews of maps in pdf format.
Ocean Portal (UNESCO) has a far-reaching list of websites related to charts and hydrography, which can be accessed through the search facility.
Office of Coast Survey (NOAA) produces a comprehensive range of charts for US waters and includes electronic navigation charts, print-on-demand charts plus products and services for Geographic Information Systems (GIS).
Earth from Space is a photographic database of NASA Space Shuttle observations. Selected photos give a glimpse of interesting Earth features and processes.
SeaWiFS Project has collected a broad time-series of satellite images of the ocean, in particular ocean colour which is related to plankton, river sediment, chemistry and current patterns.
Visible Earth is a major catalogue of satellite images covering a wide range of environmental parameters.