In Europe, considerable activities and investments are undertaken for collecting in-situ and remote sensing data from the global oceans, European seas and coastal waters, which are input for research, environmental management, and economic activities. In parallel, great progress has been made since the 90’s with marine and ocean data management, developing standards, services, and establishing dedicated infrastructures for discovery, access, and long-term stewardship. The HORIZON Blue-Cloud project as a next step aims at federating these infrastructures together with e-infrastructures in order to deploy and operate a cyber platform in support of exploring and demonstrating the potential of cloud based open science for ocean sustainability, UN Decade of the Oceans, and G7 Future of the Oceans and as a component of EOSC. One service module of the Blue-Cloud platform is the Blue-Cloud Data Discovery & Access service, which facilitates its users in finding and retrieving multi-disciplinary datasets from multiple repositories, currently: EMODnet Chemistry, EMODnet Biology - EurOBIS, ELIXIR-ENA, Euro-Argo - Argo GDAC, ICOS-Marine, SOCAT, EcoTaxa, SeaDataNet Products, and SeaDataNet CDI. This way, a common access is provided to more than 10 Million of marine and ocean data sets. Summary records of the Blue-Cloud Data Discovery & Access service are made accessible for EOSC users through the EUDAT-B2FIND interdisciplinary discovery service. Each summary includes a Source link to the Blue-Cloud service to facilitate EOSC users to find more details about available data sets per summary and to download these.