Some wave power systems can also function as break waters. The Salters duck, the clam and the Farley Triplate systems all damp the waves and are all placed at right angles to the direction the waves come from. Salters duck damps the waves by about 70% so three in a row would produce flat seas behind them. These energy producing floating breakwaters would need to encircle the sea stead and its ancillary vessels. Thus it fits in the breakwater section but as you'll see below is also a sea stead design its self. The larger the area the better because the edge to area protected ratio decreases rapidly with size. The result is a lot of wave energy to work with. However if three ranks are used the third rank of wave units may not get enough wave energy to be useful. We may not install a wave power system just big springs.
Salters duck. 
The clam is an air bag attached to the front of a floating breakwater. The wave squeezes the air in the bag in and out through a bidirectional fan (or in the original design a pair of one way flap valves feeding a unidirectional fan). It damps the waves behind it considerably.
The Farley triplate is three plates the first is half a wavelength from the second and the second and third are a full wavelength apart. All three are adjustable and tune to the average wave frequency. Because the front plate is out of phase with the other two the wave energy drives it back and forth relative to the other two. A farley triplate is theoretically the most efficient system but wares very fast and so has never been deployed commercially.
If we focus on damping the waves and not getting electricity to land then these could be optimised as breakwaters.
I also have an idea of mounting a sea stead on a salters duck. Using the ducks in two rows to support a light high structure above the waves. The duck can oscillate converting the wave action into rotational forces on a bearing. We build truck bearings routinely to handle multi-ton loads and millions of oscillations. A wall of these duck based sea steads would shelter vessels in normal seas. Where the waves are choppy because they come from a mix of directions, a Box of wave could provide a safe harbour.
New ultra-durable materials should make this possible. If we design for easy maintenance we save money. The key to using these active damping technologies is to make the energy of the waves pay for the Duck and suspension, maintenance, etc so the sea stead platform and breakwater effect is essentially free.
--184.108.40.206 12:33, 23 July 2008 (UTC)