Ocean / Sea wave energy converter system patents (over 350 patents)
http://www.enginbilim.byethost16.com/modules/articles/article.php?id=10
You could have a ball which magnetically-levitates inside a hollow-donut( the donut having an oval cross-section ), and the ball should only be free to travel in one direction, probably by using v-gates inside the donut.
The hollow-donut would float on top of the sea-waves .
( So any movement by the sea-waves should cause the ball to travel inside the hollow-donut, faster and faster, eventually, it would either, behave like a gyroscope, or, the centrifugal force would be stronger than the magnets on the surface of the ball, and cause it to physically touch the inner surface of the hollow-donut, in which case it would cease to function )
The ball could be the ball I designed below :
The 'BALL FLOATING INSIDE OF HALF-BALL MADE OF POLYGON SHAPED MAGNETS.JPG' on the following post :
http://overunity.com/16295/all-permanent-magnet-complete-levitation/msg469597/#msg469597