Galileo is one of the most important research program launched jointly by the European Commission, the European Space Agency and managed with the industry through the Galileo consortium. Galileo is a constellation of 33 satellites that will complete the fleet of 28 satellites of the American GPS and 24 satellites of GLONASS, the whole promising visibility of a minimum of 4 satellites in any place of the world, in urban or isolated zones, in the air or over oceans. Maritime environment is however hostile to signals propagation, with well known perturbation phenomena due to the very particular meteo-ocean conditions and sea surfaces status, the multiplication of metallic structures closed to receivers and antennas. The present paper presents the research and development goals, the organization of the activities and consortia, the whole being designed for welcoming foreign research centers and companies. For the maritime sector, which suffers from a lack of standard and cost efficient technologies, the challenge is to exploit the opportunity of a research program that touches most maritime activity sectors, to create a strong international innovation dynamic and consensus for the development of standard, open, technologies and services. Space and seas have lots to do together and Galileo may even sign a new area for marine applications with the design of integrated, cost efficient, global "positioning, telecommunication and information systems", combining satellite navigation with communication, observation techniques. The program provides the just framework for searching beyond current realities by a total revision of needs and solutions.