I don't know of any such visual effect. It would be interesting, I'm just not sure how it would be believably accomplished.
I don't think displaced water would actually be visible if completely under water...kind of like how displaced air isn't really visible above the water. You can see water moved where the air and water meet though.
Edit:
Unless you have a layer of salt water under a layer of fresh water, like in some of those caves in Mexico. It's the different densities that would make the water displacement visible.
Modifié par The Amethyst Dragon, 15 septembre 2012 - 06:31 .