VesselAI is a three-year EU-funded research project that aims to develop, validate and demonstrate a unique framework for extreme-scale data and AI services for the maritime domain.Using digital twin technology, the framework will efficiently fuse and assimilate huge amounts of data, enabling highly accurate modelling as well as design and operation optimisation of ships and fleets under various dynamic conditions. VesselAI will also tap into the potential of artificial intelligence, cloud computing and high-performance computing, encouraging deeper digitalisation in the shipping industry.The technologies will be demonstrated in four maritime industry pilots: global vessel traffic monitoring and management, globally optimal ship energy system design, short-sea autonomous shipping and global fleet intelligence.VesselAI comprises a consortium of renowned actors in maritime and ICT domains. Project coordinator is the National Technical University of Athens in Greece and the project consists of 13 partners in total. The partners are Kongsberg Norcontrol AS, Massterly AS, SINTEF Ocean AS and SINTEF Digital (Norway), MarineTraffic, National Technical University of Athens and University of Piraeus (Greece), Helsinki University and NAPA OY (Finland), MonetDB Solutions (Netherlands), BULL SAS (France) and UNINOVA (Portugal).The expected outcome from the project will be a unique maritime Big Data framework for processing extreme volumes of data from different sensors, ship systems, weather services, AIS data, cameras, radars, and other relevant data needed for the pilots and established digital twins that will be integrated into maritime applications. End users are fleet operators, port and coastal authorities, autonomous vessel operators and policy and decision makers.The project has received funding from the European Union's Horizon 2020 research and innovation program under the Grant Agreement No. 957237