The European Multidisciplinary Seafloor and water column Observatory (EMSO), currently participated by 8 Member States (Italy, Spain, Portugal, France, Ireland, Norway, Greece, and Romania), is a unique marine multidisciplinary, Research Infrastructure based on distributed facilities, with the goal to observe , monitor and better understand the phenomena taking place within and below the oceans, their critical impact on the Earth, and the complex interactions between the geosphere, the biosphere, the hydrosphere and atmosphere, and address the major environmental challenges. Included in the ESFRI Roadmap from 2006, in 2016 EMSO reached the status of ERIC by acknowledgement of the European Commission . EMSO coordinates facilities including data, instruments, computing and storage capacity, of diverse and numerous scientific institutes and research centers in Europe, operating in key sites in European seas, from North East to the Atlantic, through the Mediterranean, to the Black Sea, according to a common strategic framework promoting and driving advances in marine science and technology while enabling access to services provided by the facilities. Through the valuable contribution of 11 deep-sea observation systems along the water column and on the seafloor, constantly recording biogeochemical and physical parameters, and 3 test sites, EMSO makes available time series of Essential Ocean Variables (EOVs) and other physical and environmental variables, following FAIR principles (Findable, Accessible, Interoperable and Reusable). EMSO delivers and offers data and services to a large and diverse group of users, from scientists and industries to institutions and policy makers, supporting studies and providing science-based information on global challenges, such as climate trends, marine ecosystem preservation, and marine geo-hazards generation. High-quality and timely marine environmental information will nourish mitigation and protection strategies in the face of significant challenges and threats, such as natural disasters, habitat loss, human and species migration, food security, etc. EMSO ERIC aims at becoming a world-class Marine Research Infrastructure providing high-quality information on the significance and the dynamics of the deep oceans and the water column, to address global ocean environmental challenges that affect the Earth System, and impact the welfare of society.