ESONET is a Multidisciplinary European Network of Excellence (NoE) associating 50 partners from 14 countries and more than 300 scientists and engineers and dedicated to the lasting integration of research and development in deep sea observatories in Europe. Amongst other actions, it works at establishing seafloor infrastructure that will provide platforms for instrumentation deployed throughout the water column and the geosphere below in a standard manner. Those platforms will provide power for instruments and real-time two-way data communications. This preparatory phase of observatory implementation is intended to select the most suitable standards in order to develop observatories that are interoperable between themselves and which would be able to benefit from the common sharing of facilities. After the ESONET Best Practices Workshop held in Bremen at the end of January 2008, the state of art has been set and some groups working on key standardization topics have been constituted to manage standardization plans. Some outputs are presented hereafter. Those plans will be implemented and tested in the recently-selected four so-called ESONET Demonstration Missions. The ANTARES Site as an ESONET regional node offers some facilities for the next call for demonstration missions. Scientific interest is briefly explained, with a specific focus on needs for oceanography. The technical possibility of new instrument implementation via a secondary junction box is then presented.