Thanks very much for the nice comments. I used the SubSea snoot from Reefnet and both the 60mm and 105 mm lenses, full frame camera. Sometimes I used a diopter, either +5 or +10, but found I was lighting too much of the negative space. There is a smaller snoot tip that I should have used with a diopter, but only realized that after going over the images. I expect that will be a higher degree of difficulty.
Now I'm back in California, so the added challenge of surge will be interesting.