What Inventions Are Trying To Draw Energy From The Ocean Waves And Currents?

Horizontal motion of currents can be captured by turbine generators modified to catch and use ocean currents. But otherwise, they’re fairly normal. From tidal currents, same thing, but usually faster at one time, but greatly varying throughout the day.
Buoys are used to capture vertical motion of surface waves primarily through bobbing vertically. I don’t know what the specific capture mechanism is that is being used (they have been proven to work on large scales), but that’s because it’s a proprietary piece of equipment.