usSEABED is a relational database containing over 300,000 site observations of seafloor sediment and physical character information for U.S. waters from the intertidal zone to the deep ocean, including rivers, lakes, and estuaries. Data types include sediment grab samples, benthic still photographs, side-scan sonar imagery, surficial geology and sediment distribution maps interpreted from acoustic backscatter, coastal backdrop maps of U.S. coastlines, bathymetric contours, marine boundaries and coastal vulnerability. These observations contain information on sediment texture, surface pattern, benthic biota, and seafloor geology, which can help inform marine planning, ecological assessment, sea level change monitoring, and sediment movement analysis. Because many sites include direct observations, they also can be useful for validating maps derived from remote sensing methods. The data are recorded in a tabular format that can easily be imported into a traditional GIS environment (e.g., ESRI Shapefile and ASCII comma-delimited text files).