Data from the marine environment are a valuable asset for marine industries, decision-making bodies and scientific research, but in Europe marine data are stored in a wide range of national, regional and international databases and repositories using different formats and standards which makes it difficult to find, assemble and use them efficiently. The European Marine Observation and Data Network (EMODnet) is a network of organisations set up in 2007 by the European Commission in the framework of EU’s Integrated Maritime policy to address the fragmented marine data collection, storage and access in Europe. This paper introduces EMODnet in the context of EU’s Marine Knowledge 2020 Strategy and highlights some of the main features of the EMODnet Data Portals, as well as those being developed by the EMODnet central portal. Finally, the paper zooms in on the features and endeavours of one specific EMODnet activity: the EMODnet portal with access to near-real time and historical data of physical parameters.