Exerted pressures on the ocean and more particularly on the coastal and shelf seas increasingly disturb increasingly disturb coastal regions and ecosystems, and will strongly impact our future. To improve the understanding of underlying processes, the series of EU-funded JERICO (Joint European Research Infrastructure of Coastal Observatories) projects have consisted, since 2007, in continuously improving observations in European coastal marine areas where most of the world population lives, with the objective to build a pan-European Research Infrastructure (RI) providing high-quality marine data, expertise, services, facilities and observation systems. The data produced in this long-term framework are multidisciplinary, standardized, quality-controlled, sustained, interoperable, and free for access and use. However, to better serve the scientific community and address societal and policy needs, JERICO has to progress towards a structured operational European RI supported by the EU Member States (and associated members) and the EC, and endorsed as a high-value RI at EU level as part of the ESFRI roadmap. JERICO-DS will thus analyze the needs and propose a design for a state-of-the-art, fit-for-purpose, visionary and sustainable observational European RI providing expertise and high-quality data on European coastal and shelf seas, supporting world-class research, high-impact innovation, and visibility of European excellence worldwide. JERICO-DS will conceptually design the entire picture of the JERICO RI, covering both hardware and software components, and including cutting edge technologies from the sensor level to the information and service distribution to users, hence contributing to the Smart Ocean. JERICO-DS will build on nations’ will and involvement to co-construct the JERICO RI, from the scientific and technical design to the business plan and governance strategy, supporting future engagement during the ESFRI process.