So, I went back for round two. This time, the water was warmer and gin clear; and a fresh crop of alligators inhabited the pool. I still used the same rig to shoot Chris handling the alligators but without the backscatter of debris and a better understanding of what I was going for, it went without a hitch.
Here are the results. These were all shot with an Aquatica housing, 15mm Sigma fisheye, and two Sea and Sea strobes while on SCUBA.