Limiting volumetric fog to a volume

I have a water volume looking like that. I want to add a fog under the water. At first, I tried to make a post-process fog but this is a bad solution due to unreal having volumetric fog already. I created volumetric material and applied it to a particle system and now I can’t make particles appear strictly inside this box. I don’t want particles to show up on the water and block vision completely. Maybe the forum can help me with setting up such a particle system? I also want the ability to scale my water volume and have the fog adapt to that. It appears that initial location modules don’t scale with the parent component.

Box 3d is an amazing trick. I have managed to limit displayed particles to the volume. However, I am not sure how should I spawn particles in the box. Particle initial location module is not scaled with the volume, also particle blueprint parameters are half broken. They work half of the time and do nothing sometimes. I have tried to set box dimensions in an initial location with blueprint construction script and did not manage to get consistent behavior. Initial scale parameter does not work with blueprints at all. If I scale the volume, then particles scale with it too, but they are setting their scale to the max of (x,y,z) scale of the volume and that’s incorrect behavior in my case. Right now I am just sending lots of particles in all directions. I want to optimize the particle count somehow.