Snorkeling Excursion

We are in search of an excursion that offers a good amount of time in the water that offers good snorkeling (i.e. see plenty of fish, etc.). Thank you for any recommendations.

We did a 3 beach snorkel excursion through St Thomas Scuba and Snorkel Adventures. They geared the stops to the experience level of our party. We were very pleased with the time spent in the water and the quality of the spots. The guide pointed out interesting fish etc.