Allen Coral Atlas is an interactive online map of the worlds coral reefs. Registered users can identify specific study areas (less than 100 km^2) and download statistics about the coral reef health. Downloaded files include raster imagery, and vector data in GeoJSON format. Search areas can be saved for reference.
ReefBase's Online Geographic Information System (ReefGIS) allows you to display coral reef related data and information on interactive maps. You can zoom, search and query datalayers, and save or bookmark the map