I think the advanced wave animations rely on tessellation (the ones that change with the wind direction & speed), it's supposed to tessellate polys into the mesh adding more detail as well I think. If you check the "What's New in v2.x" pages in the learning center it tells a bit about it - not much. There was a problem with v2.0 where aircraft would bounce on the runways with tessellation enabled, they fixed that at v2.1 but I'm not so sure this shifting isn't a result of that fix, dunno. Previously, disabling tessellation would also disable shadows except for those associated with the user aircraft, at v2.1 they also fixed it so shadows work with tessellation off which may also have caused this side effect. I think I'm content to leave tessellation off personally, I don't see what it does to the mesh and I don't spend much time over water, but I doubt the GTX780/Titan crowd would stand for it regardless of whether they can tell the difference in the sim or not .Let me check, my laptop is not that powerful so I also tuned the settings a bit down.
What does the tessellation actually do?