Blue-Cloud: An Open Science platform for tackling global ocean challenges The European Open Science Cloud (EOSC) initiative was launched by the European Commission to provide researchers with a virtual environment with open and seamless access to services for storage, management, analysis and re-use of research data, across borders and disciplines. The H2020 project Blue-Cloud, as the "Future of Seas and Oceans Flagship Initiative", is the thematic EOSC for ocean science. Blue-Cloud delivers a collaborative virtual environment to enhance FAIR and Open Science. Started in October 2019, Blue-Cloud deployed a cyber platform via a federation of an unprecedented wealth of multidisciplinary data repositories, analytical tools, and computing facilities to explore and demonstrate the potential of cloud-based Open Science and address ocean sustainability. Blue-Cloud federated leading European marine Research Infrastructures (SeaDataNet, EurOBIS, Euro-ARGO, EcoTaxa, ICOS, SOCAT, ENA, EMODnet, CMEMS) and e-Infrastructures (EUDAT, D4Science, WEkEO DIAS), allowing researchers to combine, reuse, and share quality data across disciplines and countries. The project has developed three main technical outputs: The Blue-Cloud Data Discovery and Access Service (DD&AS) facilitates access to multi-disciplinary datasets. The DD&AS functions as a broker both for metadata and for data access, interacting with web services and APIs from each of the Blue Data Infrastructures federated in Blue-Cloud. This way, it enables users to discover first at the collection level which infrastructures might have data sets interesting for their use case, and next, to identify and download relevant data sets at granule level from those selected infrastructures, by means of a common interface. The Blue-Cloud Virtual Research Environment (VRE) enhances collaborative research. Services include Data Analytics (Data Miner, Software and Algorithms Importer (SAI), RStudio, JupyterHub), facilitating to build and run analytical pipelines, Spatial Data Infrastructure to store, discover, access, and manage vectorial and raster georeferenced datasets, and services for provenance, documenting, and either sharing with selected colleagues or make available online any generated product (e.g. analytical methods, workflows, data products, publications, notebooks). This innovation potential is explored and unlocked by a series of Virtual Labs developed by five teams of experts, addressing societal challenges in the domains of biodiversity, genomics, marine environment, fisheries, and aquaculture. The Virtual Labs showcase how Blue-Cloud can foster collaborative research in support of the EU Green Deal, the new EU Mission “Restore our ocean and waters”, and key international initiatives, such as the UN Decade of Ocean Science for Sustainable Development. The poster highlights the key services developed within the Blue-Cloud technical framework and their potential impact on marine research, ultimately promoting a sustainable and data-driven management of the ocean. This poster was presented at TNC 2022 and SciDataCon 2022