How to create a fog that darkens with depth?

I am trying to create and underwater scene, and it would help if I could create a custom fog that becomes a deeper blue with depth.
Is there anyway of doing this?

Exponential Height Fog is the best way to achieve this effect that I’m aware of. Just play a bit with Fog Density, Fog Inscattering and Directional Inscattering Color (combined with a directional light if you want to simulate some gradient light coming from water surface)

Thank you so much for the help this fog looks good now

Is there anyway I can edit the fog so everything turns darker when I move deeper, and it eventually turns completely black?
Thanks again for any help

Here’s a quick example that I just made. I performed this in the level BP, but you could easily do this is just about any BP that can access the player character and set the exponential fog.

Some quick notes:
The color variables are linear color, not the regular color.
The fog depth range is the distance over which you want to transition like 5000 units down.
Fog depth z thresh is just the Z starting point for your water’s surface. You could also change this part to get the world Z position of the water plane if you like.
Fog update rate is just set to 0.1 in my case. Set the value as high as you can before it starts making a visibly choppy transition.

Hopefully this gets you started

EDIT: oh and if you do this in the level BP, you can select the fog actor in the level editor, then go over to the level BP, right click and at the top of the context menu, it should say something along the lines of adding a reference to the fog actor.

Thank you for the help, but I am having trouble setting up the fog, I have tried experimenting with the variable values but I can’t seem to get the fog to blend, it only shows up as either the start or end colour. Is there something obvious that I missed?

This is a technique using fog cards