OpenStreetMap (OSM) is a collaborative project to create a free editable geographic database of the world. The geodata underlying the maps is considered the primary output of the OSM project. The creation and growth of OSM has been motivated by restrictions on use or availability of map data across much of the world, and the advent of inexpensive portable satellite navigation devices. EMODnet bathymetry considers OSM to be the best source for land data to complement the marine environment and to allow easier navigation in the data portal.

OpenStreetMap is a free and noncommercial project; everyone can just download OpenStreetMap data free of charge and process it. However EMODnet Bathymetry requires a tailored rendering of OpenStreetMap data as in all standard available visualisations the world oceans are obscured by water features which have no use in a marine environment. In addition, EMODnet requires a non-projected rendering with no land use which is not the OSM render default.

The OSM rendering is provided to EMODnet by the German company Geofabrik (www.geofabrik.de).