The beginning of 2020 finds Artificial Intelligence, HPC and Big Data at the forefront of digital transformation. The maritime industry is embracing them wholeheartedly due to their true potential to meet the ever-increasing and complex traffic and shipping demand for safety, performance, energy efficiency, automation, and environmental impact. Meanwhile, shipping generates extremely large amount of data every minute, which potential, however, still remains untapped due to the involvement of enormous stakeholders and the sophistication of modern vessel design and operation. The key to addressing these challenges lies in research and innovation, especially in novel algorithms, tools, and platforms within the areas of AI, HPC and Big Data to unlock the new possibilities of a diverse range of current maritime applications for vessel traffic monitoring and management, ship energy system design and operation, autonomous shipping, fleet intelligence and route optimisation, and so on. While digital transformation is progressing rapidly in all aspects of society, it is now the right time to unlock the potential of extreme-scale data and advanced technologies to address the high computational, modelling and data processing demands required for accurate modelling, estimation and optimization of design and operation of ships and fleets under various dynamic conditions in a timely manner. To tackle all the above-mentioned challenges and opportunities, VesselAI has the objective to develop, validate and demonstrate a novel holistic framework based on a combination of the state-of-the-art HPC, Big Data and AI technologies, capable of performing extreme-scale and distributed analytics for fuelling the next generation digital twins in maritime applications and beyond, including vessel motion and behaviour modelling, analysis and prediction, ship energy system design and optimisation, unmanned vessels, route optimisation and fleet intelligence.