With funding from the National Science Foundation and the National Science Digital Library, the Scripps Institution of Oceanography (SIO) is working to make available via the Web all data, documents, and images from SIO expeditions dating back to 1903. The SIOExplorer project, which ultimately will become part of the National Science Digital Library, is a collaborative effort of researchers, computer scientists, and librarians from SIO, the San Diego Supercomputer Center, and the UCSD library. Visitors to this site may download several data access (e.g., CruiseViewer and Webform, graphic and text-based search interfaces), metadata (e.g., MOBE, a metadata browser and editor, and COBE, a canonical object browser and editor), and visualization tools (e.g., GridViewer). Types of datasets available include shipboard data (e.g., multibeam swath mapping data, dredges, cores, currents data, seismic profiles, sediment thickness, etc.), historical material (e.g., expedition photographs), geophysical and geochemical data (catalog of seamounts of the Pacific Ocean), educational data, and metadata resources.