BLACK swimming pool water problem - YAFRAY
I have solved this similar problem before, but for some reason, this time, I can’t get this particular project to work. Any help is appreciated. Thanks.

Here’s the BLEND file to tinker with…
(Right-Click and save)

Unable to download your file, but what do you have Raydepth at?
Try increasing it.

You may need to Right-Click the link and save it.
Anyhow, I can’t find the RayDepth when using Yafray to render the image.

For the RayDepth : When you select Yafray as the renderer in the Scene panel, 2 yafray-related tabs appears under the Render tab. In the 1st one you’ll find the Raydepth setting. (yes, it’s a scene setting, not a material setting)

Thanks, I may end up using Full GI (that does work, but takes a long time), but now I have to figure out why Yafray quit working with the newest version of Blender.