The oceans represent a huge energy reservoir consistent of stored solar and gravitational energy in several forms, causing ceaseless movements of an enormous volume of water. This energy is generally diffuse but, in many cases, significantly more concentrated than other forms of renewable energy already being successfully exploited on land. Among the ocean-energy resources, wave and marine-current energy emerge as the most promising options for massive ocean-energy generation in the immediate future. The main objective of this paper is to focus on trends that can lead to a feasible massive marine-current-power future scenario, and to introduce a technological solution which could help to reach that goal. We shall describe the main features of a floating marine-current-power system that introduces conceptual innovations in order to improve the technical and economical performance.