This paper has an objective to combine and disseminate information on sea wave energy converters. The potential of sea wave energy is very high and over one thousands patents exists, however, only selected projects supported by EC are presented. At the beginning a basic terms and methods of sea wave energy capture are discussed. Further several most important sea wave energy conversion prototypes are shown. The generators and power electronics solutions for Power Take Off system are presented on the example of Wave Dragon MW sea wave energy converter. The Wave Dragon MW captures power from the sea waves by means of low-head turbines and converts it into rotating mechanical power. Problems which can appear in mechanical power to electrical power conversion in Wave Dragon MW can be expected to be similar as in wind turbine. However, subject of the mechanical energy conversion from sea waves to electrical energy is not well identified and further research should be curried out. Additionally, specific problems of grid connected AC-DC-AC converters under grid voltage distortions (harmonics and voltage dips) are discussed. Some simulated and experimental oscillograms that illustrate properties of the presented systems are shown.