I just returned from a week on the Jardines Aggressor. It was an absolutely amazing boat with an incredible crew. Nothing but the most positive reviews possible for them based on my trip. We had a couple who had done three other aggressors last year and they agreed this boar was by far the best they had been on.
The Aggressor folks recommended tipping at $400.00 per diver, which is a little less than 10% of the $4500 retail price. I got a special deal on a last minute spot at $3,000.
But I tipped $450.00. I can tell you that, as hard as the crew worked to make the trip great, it was worth every penny. Because of the economy, the people on the island have very little and the tips are divided equally among the crew of 8.
The Aggressor did not offer any "special services" to any individual photographer, or, at least, no one on our trip asked for anything like that. Maybe some of the other liveaboards do. That might require an extra payment or tip.
Enjoy your trip! The diving was fantastic.
Also, the Aggressor allowed you to tip in $U.S. So no need to exchange for CUC and pay the 10% extra penalty.