Over the past few month I've been chipping away at an improved Underwater Volumetric Fog solution for WaterlinePRO. The objective was to have something that has no visual artifacts, great visuals and great performance in the end things worked out pretty well, though there is room for improvement as always :P
The cool thing is that the caustic effects are generated in real-time based on the FFT ocean simulation, so essentially all visual aspects are driven by physical parameters like wind direction, speed, contribution, gravity and amplitude!
You can checkout WaterlinePRO here: https://www.unrealengine.com/marketplace/en-US/slug/waterline