During the SO268 cruise, 17 CTD casts were carried out in the German and Belgian working areas using a SBE 911 plus CTD profiler attached to a Sea Bird SBE 32 carrousel water sampler. CTD water column profiles were obtained to get information about general physico-chemical composition of the water column (i.e. the vertical variability of temperature, salinity and oxygen) and to select the appropriate water depths for water sampling. The registration of the hydrographic parameters was performed from the sea surface down to the sea bottom.