A model for a double pendulum Wave Energy Converter (WEC) for drifter applications has been developed and validated. The WEC is composed by an articulated arm, a gear train, a flywheel, a one‐way bearing and a DC generator. Due to the one‐way bearing, the system may have 3 or 4 DoF. The corresponding equations of motion have been obtained through the Lagrange formulation. The model has been experimentally validated on a long‐stroke shaker by emulating part of a drifter’s motion under wave’s excitation. This motion is in good agreement with the simulation results prior conducted with OrcaFlex package.