The objective of SubCoast will be to develop a service for monitoring the extent and impact of subsidence in coastal lowlands and demonstrate its capability in various pilots for a variety of settings around Europe. The service will be designed to appropriately determine the effects of subsidence on current and future floodrisk in coastal lowlands, monitor the integrity of coastal barrier systems and infrastructure and assess the impact of subsidence due to natural or man-made causes (groundwater pumping and oil/gas production) on land use and hydrology. SubCoast will be built on the heritage of GMES Service Element ‘Terrafirma’ and use the full capability of PS-InSAR as a earth observation technology for large scale subsidence mapping. Necessary R&D will be focused on possible augmentation of datasources and the improvement of retrieval algorithms. Subsequent validation efforts will make full use of the Terrafirma Validation Testsite and other current validation initiatives. A distributed data and information system will be set up which facilitates the accessibility and operability of EO-data, in-situ data (including geoscientific data) and model results for the selected areas. SubCoast will orient its services along existing guidelines established in previous GMES-projects, notably ‘Terrafirma’, and in line with relevant directives at European Level. End-user involvement will be realised by establishing a user federation which holds the most directly involved regional, national and European stakeholders.