EurofleetsPlus will facilitate open access to an integrated and advanced research vessel fleet, designed to meet the evolving and challenging needs of the user community. European and international researchers from academia and industry will be able to apply for several access programmes, through a single-entry system. EurofleetsPlus will prioritise support for research on sustainable, clean and healthy oceans, linking with existing ocean observation infrastructures, and support innovation through working closely with industry. The project will enable access to a unique fleet of 27 state-of-the-art research vessels from European and international partners. Through competitive Calls, researchers will be able to access the entire North Atlantic, Mediterranean, Black Sea, North Sea, Baltic Sea, Pacific Southern Ocean and Ross Sea. In addition to ship time, researchers will also have access to new Autonomous Underwater Vehicles and Remotely Operated Vehicles. A unique portable telepresence system will enable remote access by researchers and diverse end users including the public; a first for Europe. In addition to comprehensive transnational activities, the project will undertake joint research activities to meet the evolving challenges of marine research, in particular, deep ocean research and exploration, data management, and virtual access. Multiple networking activities will ensure robust Call processes; wide stakeholder engagement; development of a strategic roadmap and long-term sustainability plan; diverse training and education activities; management of innovation; and widespread dissemination and communication. EurofleetsPlus will facilitate access to unique marine infrastructure, enabling excellent research, increasing ocean literacy, and providing a clear road map for the continued integration and advancement of the European research fleet.