Hi, Spaceman. How much of this 30-odd hours is taken up by the rendering of the water plane to horizon portion?
I think that quite a lot of that time could be removed by masking out the water under terrain.
And even still, that seems like far to many hours for this render, unless it's rendered much bigger and scaled down for uploading here?
If you like, send me the .tgd(minus the models but send the terrain if it's a heightfield) and I'll do your subterranean water mask. That should take off lots of the time it takes to render the lower 1/3rd portion. That should remove 2/3rds of the render time of that bottom section, because there is a lot of terrain covering that water plane, imagine the lower third like 3 triangles, you really only need to render the middle one here.