Sea-bed substrate map, sediment accumulation rate map and case studies of the EMODnet-Geology study area. The sea-bed substrate map of the Baltic Sea, the Greater North Sea and the Celtic Seas is presented at 1: 1 000 000 scale. The sea-bed substrate map is collated from more than 200 separate sea-bed substrate maps. The sediment accumulation rate map of the Baltic Sea and parts of the Greater North Sea shows point-source data from more than 600 sea-bed sediment sampling sites. Six case studies emphasize the importance of marine geological information, local features and detailed surveys in marine spatial planning and use of marine resources. The maps and case studies are collated and compiled within the EMODNET-Geology project.