Karen,
We did Stingray City in May with our DS17 & DS13 and it was amazing!!! I don't know why they even give you snorkels. All we did was wear them on top of our heads. You're only in 3-4' of water and the stingrays swim right up onto your outstretched arms. You don't have to even put your head in the water. When we approached Stingray City on our boat and saw all the stingrays, I'm thinking, "Ummmm....I'm not sure I'm really wanting to do this." It was just sooooo cool! They are so graceful and gentle. They just glide along you. They're underbellies feel just like velvet. They don't have teeth so feed by suction. DS13 fed them and got a hickey on his wrist. I told him it had better have been his first.
We snorkeled at Chankanaab Park in Cozumel. Our guide showed us all kinds of fish and stingrays and even Barracuda.
The coolest place to snorkel, though, is
Castaway Cay because the statue of Mickey is out there.
I'd never snorkeled before our cruise. The guide in Chankanaab gave us a lesson and now I LOVE IT!!! By looking through the mask, you forget that you are right there with these creatures. It's almost like you're looking through a window. The fear factor, if there is one, disappears and you just relax and enjoy nature. Try it!

Linda