This could also be implemented on any river. Simply substitute the floatation devices with a paddlewheel attached to a turbine.
It takes very little electricity to separate the hydrogen from the water. We did it with twelve measley volts in seventh grade.
Besides, there are plenty of hydro electric dams in the world. Every river that can be damed- is.
What you seem to be miising though is the efficiency factor.
Can power be generated that way? Sure. Is it cost effective given the capital investment? Not even close.
I wouldn't think you couldn't get too many rpms on a shaft/cam setup with wave action...Seems the best you could do would be milivolts...I'm curious how this works...