The SOLEMIO data buoy is an automatic profiler buoy originally designed to monitor the high frequency variability of coastal waters (impact of intensive fresh water discharges, dynamics of a fast phytoplankton bloom, storms, seasonal stratification…). The system is located at the outlet of the Bay of Marseille (43°14 N – 5°17 E), area influenced both by marine coastal waters, and sometimes by fresh waters from small coastal rivers and from the Rhone River. The measuring station is equipped with high performance systems for seawater analysis and near real time data transmission. A multi-sensor probe (SMATCH 2011- 2021 and WIMO since 2021) carries out hourly measurements in the water surface (temperature, salinity, turbidity, chlorophyll fluorescence) . A profiler (Provor NKE) moves daily along a cable between the surface and 50 m depth  in order to achieve same measurements over the entire water column. .Precision estimated of the complete data collection process is : temperature (±0.1°C), salinity (±0.1), in vivo fluorescence (±10%), and turbidity (±10%). All collected data are automatically transmitted daily and viewable on the Web site:  http://mio.pytheas.univ-amu.fr/?-Observation-marine- The surface buoy is equipped with meteorological sensors (wind, temperature) and houses electronic system (power, control box , data transmission) . It also provides suitable mounting for a large solar panel that recharges a battery bank. The buoy is also fitted with a meteorological station. The SOLEMIO station is a component of the national high frequency coastal observing network COAST-HF (http://www.coast-hf.fr) from the ILICO research infrastructure (http://www.ir-ilico.fr) . Data can be displayed and downloaded on the website: https://www.coriolis-cotier.org/