This paper proposes a specific hybrid 2-D simulation model of magnetic field distribution accounting for magnet skew in the case of a linear permanent magnet generator (LPMG). The proposed methodology is based on a hybrid numerical technique implementing standard finite elements for the analysis of stator and rotor parts combined with an analytical solution in the Cartesian coordinate system in the air-gap area specified for magnet skew consideration. The developed technique has been incorporated in a coupled field-circuit model for the overall simulation of the performance of an electrical generating unit for sea-wave energy extraction using LPMG. The derived model has been implemented in the control subsystem aiming to tune the movement of the wave energy absorber to the system resonance frequency enabling to optimize its performance. Simulation results have been validated by measurements on a sea-wave energy extraction demonstration plant.