Great video! Here's a nooby question though, why don't the oceans settle down? Is it to do with the moon? And does this mean oceans on planets without moons are perfectly calm?
Ocean currents exist because different places on Earth are at a different temperature, and therefore the water will feel a pressure force to go elsewhere.
This is quite a generalization, but meteorology is a complex science, and there is much to dig in.
The most famous of these uneven forces is of course the Coriolis effect.