SeaDataCloud aims at considerably advancing SeaDataNet services and increasing their usage, adopting cloud and HPC technology for better performance. More users will be engaged and for longer sessions by including advanced services in a Virtual Research Environment. Researchers will be empowered with a collection of services and tools, tailored to their specific needs, supporting marine research and enabling generation of added-value products. Data concern the wide range of in situ observations and remote sensing data. To have access to the latest cloud technology and facilities, SeaDataNet will cooperate with EUDAT, a network of computing infrastructures that develop and operate a common framework for managing scientific data across Europe. SeaDataCloud will improve services to users and data providers, optimise connecting data centres and streams, and interoperate with other European and international networks. SeaDataNet projects: SeaDataNet (2006-2011); SeaDataNet2 (2011-2015); SeaDataCloud (2016-2021).