ESONET is an European network of excellence (NoE) associating 50 partners (research centres, universities, industrials and SMEs) from 14 countries: France, Germany, Italy, UK, Spain, Portugal, Greece, Belgium, Ireland, the Netherlands, Norway, Sweden, Bulgaria and Turkey. More than 300 scientists and engineers will participate to its activities. The goal of the ESONET NOE is the lasting integration of European research on deep sea multidisciplinary observatories. Over the initial 4 years, the approach will be to merge the programmes of members organisations through research activities addressing the scientific objectives and networking activities specially designed for integration and spreading excellence.