Hello- I have been to there 5 times. I snorkel every time. I carry my own equipment but you still need to get a snorkel vest for free from the snorkel shack. I don't mind it, then i can relax and float a bit.
There are lots of fish. If you go to the first alcove of chill beach? I do not know what to call it. You will see a floating dock, swim out further and there is a shipwreck. The lifeguards are on jet skis out there. You will see the area. The snorkel shack people can guide you (which is right before chill beach). That cove is the best place for snorkeling that I know of someone may know different. Some days are clearer than others of course. I bring my own snorkel gear because it has the bobble where water can get in as I swim around.
Don't forget to shuffle your feet! Have lots of fun.
Let me disclose I have only been there with Royal- Food on the island is the buffet style ship food. Its included. It is so nice to eat there on the picnic tables. I love it. They usually have water, ice tea, lemonade included. Royal makes homemade tortilla shells. I hope Celebrity does the same. There is snack shack in the back included as well that my son visits every time.
Enjoy!!