Well, it turns out that the water shader goes apeshit when active during the Stopwatch's inversion code.
This is just one of the many things that go bananas.
It will do this forever. Ugh.
While I could probably fix it after a stupid long time of workarounds, I'm not going to. It's not a massive priority if the water is bendy or not. I'm going to miss it, but that's part of game design; you've got to be willing to make sacrifices and concede on shit you like for the better whole of the project.
So now the water's back to being this. It's not a horrible change, but still.
Sorry for the lag. Used GifCam rather than my record-to-video-then-convert-to-gif method. Not making that mistake again.