Moving 6-year analysis of Water_body_dissolved_oxygen_saturation in the North Sea. Four seasons (March-May, June-August, September-November, December-February). Every year of the time dimension corresponds to the 6-years centred average of each season. Data Sources: observational data from SeaDataNet/EMODnet Chemistry Data Network. Description of DIVA analysis: Geostatistical data analysis by DIVA (Data-Interpolating Variational Analysis) tool, version 4.6.11. A reference field of all seasonal data between 1980-2017 was used; results were logit transformed to avoid negative/underestimated values in the interpolated results; error threshold masks L1 (0.3) and L2 (0.5) are included as well as the unmasked field. The depth dimension allows visualizing the gridded field at various depths.