Power-generating system based on successive hydroelectric turbines (∫1N) located parallel to the submerged section of the hull of vessels and/or submarines (generating line ∫1N), at the point or points of greatest channeling of the water flow produced naturally during navigation. Each turbine is preceded by a propeller (∫1N), whose function is to increase the speed of the water flow powering the turbine when the vessel and/or submarine is in motion, and to generate the power flow when the vessel and/or submarine is stationary (anchored or moored).