Systems are provided for obtaining electrical energy from sea waves using deflectable material, especially EAP (electro-active polymers) type SSM (stretchable synthetic material) that generates electricity when an electrostatic charge is applied to the polymer and it is stretched. In one system (10), a buoyant element (12) has upper and lower parts (14, 22) connected by a quantity (36) of SSM, with the lower part anchored at a fixed height above the sea floor (24) and with the upper part movable vertically to stretch and relax the SSM as waves pass over. In another system (50) the buoy is rigid, but is anchored to the sea floor by at least one line (60) that includes, or is connected to at least a length (64) of SSM material. In still another system (160) a plurality of rigid buoys (162) that float on the sea surface, are connected in tandem by SMM (166, 172) that is stretched and relaxed as the buoys pivot relative to each other in following the waves. The buoys preferably lie with at least 80% of their volume below the average sea surface.