Maritime surveillance (MS) is defined as the ability to monitor the activities within the maritime domain and to ensure, when required, a timely decision process. MS is involved in diverse fields such as: fisheries control, border surveillance, maritime transport safety or monitoring illegal oil spills. MS is usually made possible by combining information from a range of different data sources. Generally, information collected by vessels, airplanes and satellites is employed in MS. Nowadays, the systematic revisit of satellite imaging sensors and their capability of covering large areas of the sea with unprecedented spatial resolution enable a satellite-based monitoring of the worldwide activities within the maritime domain. Synthetic Aperture Radar (SAR) imagery are widely used to monitor the maritime domain and various SAR-based applications such as ship detection or oil spill delineation are available as operational services integrated into near-real-time processing chains. In this context, the Sentinel-1 SAR satellite constellations from the ESA Copernicus program with its main assets: open access data policy, 3-4 days systematic revisit time and multiple acquisition modes, enables a systematic monitoring of activities within the maritime domain. In addition, Sentinel-1 time-series can be used in identifying changes of coastal areas and borders.