Hi @da13d3ac0n, welcome to the community!
I’m afraid that Google Photorealistic 3D Tiles does not contain a water mask, so the water material is never applied.
If you want to simulate a water effect, you may need to do in the typical Material slot. We’ve never tried to develop a material for this, but perhaps you could check for blue hues in the texture, and apply your water effect to them? 