We waited until our last day on the island -- May 6 -- to hit Cemetery Reef (or Cemetery Beach). This was by far the most spectacular snorkeling I've ever done. The fish -- mostly sargent majors -- would swim right up to you and then some would follow you around. All kinds of fish were in abundance and they weren't the least bit bothered by our presence.
I'm not well versed in the types of tropical fish (there were so many), but spotted a stingray close to shore as I was coming out, and
two squids were hanging out by the shore.
The water was clear and calm. The beach itself was clean and not crowded at all. By mid-afternoon, though some locals had arrived with
blankets and provisions. Wish we hadn't waited until our last day as I would have made a second visit.

