My niece and I used ZumaTours for our snorkeling trip to Tortuga in part because they were the only company to quickly respond to my email inquiry (the others took over a week). And the price was reasonable for what we got. Our first stop was nice, but there wasn't a lot to see. However, the second location was amazing. A large number of sea creatures, but there were also a large number of land creatures as well. I know this is something they can't control, but be aware, you won't be alone. Lunch was very tasty. The reason I didn't give an excellent rating is that the time on the island after lunch was way too long (2 hours). There is very little to do and the water is too cloudy to do any more snorkeling. Also the guide did not instruct customers to not touch and pick-up sea creatures, somthing I believe is important to the health of the animals.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.