This is not a specific criticism of Surfit's tour. They are one of five outfitters all running tours out of the same launch point. They do a good job, and our guide was a great guy. The problem is that all of that tourist pressure on the area has seemingly chased off much of the wildlife. We saw nothing of dolphins or manatees, and that seems to be much more the rule than the exception. The mangrove tunnels are so heavily trafficked, there is little to see in there but lots of black crabs on the trees, and some washed out whitish sponges underwater.
It is fun, and the guides make the best of it, but go in with low expectations and it will more likely meet those expectations.