The overall objective of the project is to develop a virtual environment equipped with FAIR multi-disciplinary data and services to support marine and freshwater scientists and stakeholders restoring healthy oceans, seas, coastal and inland waters. The AquaINFRA virtual environment will enable the target stakeholders to store, share, access, analyse and process research data and other research digital objects from their own discipline, across research infrastructures, disciplines and national borders leveraging on EOSC and the other existing operational dataspaces. Besides supporting the ongoing development of the EOSC as an overarching research infrastructure, AquaINFRA is addressing the specific need for enabling researchers from the marine and freshwater communities to work and collaborate across those two domains. A specific goal of AquaINFRA will be to develop an EOSC based research  infrastructure combining the marine and freshwater domains, which will include the development of a cross domain and crosscountry search and discovery mechanism as well as building services for spatio-temporal analysis and modelling through Virtual Research Environments. A set of strategic use cases including a Pan-European use case as well as more focused use cases in the Baltic Sea and the North Sea will provide the setting for co-designing and testing services in the targeted research communities. The AquaINFRA project results are expected to contribute to the utilisation of EOSC as an overarching research infrastructure enabling collaboration across the domains of marine and freshwater scientists and stakeholders working on restoring of healthy oceans, seas, coastal and inland waters.