Realistic Water Bubble Simulation

https://youtu.be/O-52enqUSNw

At 2:30, he marvels that adding realistic air - water interaction requires such a simple calculation: "...one unified technique to add foam, spray and bubbles..." 

3:49 " ...bubbles and foam appear at the regions where air gets trapped beneath the surface...at wave crests...by looking for regions where the curvature of local fluid geometry is high and locally complex" 

This simplification allows the bubble effect to be added or taken away in post-processing, meaning that after 40 hours of rendering, the bubbles can be added or subtracted without having to render the entire simulation again. He illustrated this at 3:14. 

Here's his subsequent video on bubbles simulation.

https://youtu.be/MD_k3p4MH-A