The E1-M3A station is located 24 nautical miles north of the island of Crete anchored at a depth of 1,400 meters. The Cretan Sea is an area of intermediate and/or deep-water formation dominated by multiple scale circulation patterns and intense mesoscale variability. Such areas of water formation are key locations for monitoring of the Mediterranean biochemical functioning. The wintertime convective mixing of the water column and the exchanges of water and mass (diluted, suspended or near-bed) with the adjacent Levantine and Ionian Seas through the straits of the Cretan Arc, make the Cretan Sea the poorer in nutrients and the richer in oxygen among the principal basins of the Mediterranean Sea. Among the extensive suite of measurements (atmospheric and marine) there are CTD data down to 1000m, Chl-A, DO and turbidity data for the first 100m of the water column while the recent addition of surface pH and pCO2 sensors further expanded the biochemical component of the station.