MAREL Carnot station is a high frequency monitoring station installed in the harbour of Boulogne-sur-Mer. It measures several parameters every 20 minutes, including : salinity, water and air temperature, fluorescence, turbidity, dissolved oxygen concentration, percentage of oxygen saturation, P.A.R., relative humidity, wind direction and speed, as Well as water height. On the other hand, nutrients such as phosphate, nitrate, and silicate are measured once every 12 hours. The purpose of this report is to present the main elements that future users will need to know so that they can adjust their research according to the quality of the data and their objectives. The results of the measurements of various physiochemical parameters on the period 2020-2022 are shown in more detail to highlight the seasonal cycles characteristic of this ecosystem.