Oscillating Water Columns
Oscillating water columns function by using an air chamber instead of a hydraulic pump. The swells of the waves cause the air in the chamber to compress and flow through a turbine. The turbine and generator in turn convert the energy into electricity.http://www.alternative-energy-tutorials.com/wave-energy/wave-energy-devices.html
Over-topping Devices
Over topping devices function by using the waves to fill a reservoir of water in the device to a higher level than the water surrounding it. The device mainly uses the natural velocity of waves to force the water into the reservoir. Once the water is captured, the potential energy of the water in the device is then used to force water through a turbine. In this manner, the device functions very much like a miniature continuously refilling dam.en.openei.org/wiki/Marine_and_Hydrokinetic_Technology_Glossary