Very often when moving around, I find myself "floating" on land. In some caves, this is especially bad. I find myself clipping out of and back into the cave. Whenever it happens, I see a dark blue-green color flickering on and off my screen, and it looks like I'm toggling between swimming and walking. This has made the game nearly unplayable, and google has sadly failed to assist me.

So far, it seems like the game thinks I'm in two places at once, because, whenever it starts happening on the overworld, I hear running water noises popping in and out. This has only started happening after the latest patch. I'm not running any mods, and I've tried a completely fresh install, yet I still keep getting it.

Any ideas?

The issue you are describing sounds like a problem I read about some people having when they manually disabled vsync in their GPU profiles. Make sure vsync is set to use application and it is on.

Vsync was indeed set to Off in my GPU profile. I'll see if that works.

EDIT: Nope. I still seem to have the issue, though, my in-game FPS still goes above 60.

EDIT2: I set it to 'on' instead of 'use 3d application settings', and it worked. I went to one of the problem's hotspots, and nothing happened. Thanks a bunch.