This doesn't look like much, but it is the ISWEC, the Inertial Seawave Energy Generator, developed by Wave for Energy, a spin-off of the Politecnico di Torino in Italy. It is a very clever electrical generator that converts the rocking motion caused by waves into rotary motion that can generate electricity.
Most wave generators, like the Pelamis, have articulated joints that move with the waves, but can be hard to seal against seawater, and can leak lubricating oils.
The ISWEC does not; it uses the principle of the gyroscope, which when spinning resists change in direction. The wave motion induces a roll in the gyroscope, which is connected to a generator. The action is completely internal to the hull of the wave generator, and is remarkable to watch; as the hull rocks, the spinning gyroscope rolls around like the spacecraft in the science fiction movie Contact.
In this incredibly cheesy early video (they had a better one at the Fluidtrans show in Milan) you can see a 1/45 scale model in action. They are now preparing to test the 1/8 scale model in the Mediterranean Sea. More at Wave for energy