Persistent Visual Bug

[Privateer]

I can't seem to narrow this down and am hoping someone more knowledgeable might have an idea. As you can see in the screenshots below there is this weird bug with the water on the left hand side of the screen. It persists across fresh installations both vanilla and different mod configurations. Being a Steam copy I thought it might be a saved shader so I cleared out the Steam shadercache and the Windows DirectX cache but it's still there. Any ideas?