I came across two videos on you tube the other day, that in combination have made me a big fan of this type of wave energy system. The way it works is by creating a large concrete box that is open only below the surface of the water, and when the waves rise and fall on the shore, the air pressure causes turbines to spin. I saw the over view of that system and it sounded really cool as well as simple. then I saw and actual video of the turbine moving in real life, and it produces much more energy than I would've thought. I recommend taking a look at both to really get the full impact.

Video #1 - Overview
YouTube - MrKeepthelightson's Channel
Video #2 - Real life shot of turbine
YouTube - MrKeepthelightson's Channel