summary: The European Station forTime-series in the Ocean, Canary Islands (ESTOC) is a sustained and multidisciplinary observatory located at the east central North Atlantic. The ESTOC goal is the creation of an Eulerian long time series on an inter- and multidisciplinary basis in order to monitor and help understand oceanic long-term variability in the North Atlantic subtropical gyre. ESTOC is providing hydrographic and biogeochemical time-series datasets from 1994. Activities include a ship-based observation program (observations of physical, chemical and biological parameters) and one moored structure with meteorological and oceanic surface observations, as well as in the water column.