Thanks, feel free to email me if you can dig up anything or ever want to spitball ideas. Email address is in my profile.

I've poked around lightly and didn't see anything vis a vis holographs, but I'm going to do a second pass - someone has to be onto this path in some paper somewhere.

No evidence whatsoever, just intuition.

If Alice and Bob are both cetaceans, communicating via underwater acoustics, what are they trying to say to each other? And do they understand each other?

I guess my thought is that non-symbolic communication in the black and seamless sea implies something more.