I snorkeled for the 1st time ever at CC 2 weeks ago, and I wish I was there right now. I'm a terrible swimmer, and was nearly hyperventilating when I started out of fear of death, stings, sharks and (gasp) embarrassment, but it truly was a highlight. Literally, I was out there for nearly an hour, saw Minnie, a treasure chest, a bunch of cannons, and lots of other cool stuff. Mostly though, it's the marine life: colorful fish, anemones, etc . . . Once you leave shore, you have to get past the area of plants which are on a sandbar only a couple feet deep, and then it gets good. this means going out maybe 30 to 50 yards, over the plants, and then it opens up.
The Lifeguards are excellent, the waves are minimal, and even a lead butt like me with a farmboy's fear of "over my head" water considered it a highlight.
Also, there's always a friendly lifeguard walking on the snorkeling beach to answer any questions. One tip, push down on the tip of the inflation tube to blow up your life jacket. I kid you not, I wish I was there right now, and I am a bad bad bad bad swimmer. By the way, there do not appear to be any sharks or stingy creatures. And, yeah, it's about $25 for the full equipment. Definitely rent their flippers because they are heavy and horrible to pack.