Basically it works like this.
The Oyster 2 is anchored to the seafloor about half a mile off shore. Near-shore waves pound against its frame and engage the hinge mechanism. The hinges engage two hydraulic pistons that are connected to hydroelectric plants onshore. Essentially the Oyster turns offshore wave power into onshore water power. The first prototype Oyster 1 was installed and tested in the summer of 2009 and Aquamarine Power used information from that test to vastly improve their design. The Oyster 2 is simpler in design, has fewer moving parts, generates 250% more electricity and is easier to maintain.