I dove Sting Ray City about 7 years ago. (I wasn't on a cruise at the time, but staying at the Sunset House resort.) I don't remember the name of the company now and don't know if you still can do it. We went to a place where the water was about 15' deep. It was a fun and interesting experience. We had to remove our snorkles and dive knives before going in. The dive master had a container of pieces of some kind of strong-smelling fish and showed us how to hold it in our closed hand and wave it around to entice the rays, then when we were ready to feed them to open our hand out perfectly flat so they could swoop over it and remove it. It was a funny feeling, kind of like having your palm scraped with fingernails. They swam all over us, rubbing against us. They're very soft. I'm sure if you do a Google you can find out if it's still available.