The paper presents the design procedure and modeling of performance for a special coupled electromechanical system, for use in sea wave energy extraction applications. The electromechanical system is consisted of a linear permanent magnet generator (LPMG), combined with a cylindrical floating buoy moving due to the sea wave incidence. The basic advantage using LPMG for sea wave energy extraction applications is that the generator exploits directly the vertical movement of the incident sea wave. In such a case, the linear generator is directly coupled with a vertical cylindrical buoy in heave. This topology involves a lighter and simpler mechanical system, in comparison with a complex system that converts the vertical linear movement of the sea wave to rotation, in case that a rotating generator is used. In order to efficiently exploit the wave energy using a point absorber like a floating buoy, it is important to tune the movement of the coupled mechanism, with the main frequency of the incident wave by using appropriate control. The system analysis requires particularly developed electromagnetic - mechanical - hydraulic simulation models for the time variation representation of the system's operational parameters.