We did the Everybody Loves Rays excursion in Cozumel and I heartily recommend it. You meet at the pier and take a very short taxi ride to the place. Since we were a large group they split us up into two groups. One group snorkeled while the other learned about the rays and vice versa. The reason I prefer this excursion over the one in Grand Cayman was the fact that the area was sheltered from much wave action. The guides took great care of the Rays. I have seen pictures where people in Grand Cayman are holding the rays up and out of the water and this is very stressful for them, akin to someone holding your head under the water. The guides were knowledgeable and had us first pet the rays, then feed them, then hold them (at the surface with their gills still under water). They took a variety of pictures of everyone and these were available as single prints for $10 or all the pictures on a CD for $25. The fellow who prepared the CD corrected for under or over exposure on the shots and the CD contained some very good professionally done underwater pics of the Rays. BTW the barbs are clipped here as these rays are captive. One of the families had previously done the Stingray City tour in Grand Cayman and they said they much preferred this tour. When they did Grand Cayman it was very crowded with not so many rays and very unorganized. Especially for kids or the elderly this excursion in Cozumel was educational, fun, and very much controlled, safety wise.
The snorkeling part was fun as a guide periodically fed the fish and rays so they would swarm around him. You are allowed to use your own camera in this part. After both groups were finished, which took about an hour, anyone who wanted to could go out on a water trampoline. There were hammocks available to lounge in, hermit crab races for the kids, a free soda, and snacks for purchase. There was a fellow weaving personalized wrist bands and massages were available. There were freshwater showers and clean bathrooms. Your wrist band also got you a free (very small) margarita in Margaritaville on the way back to the ship. I had the Fish Tacos there and they were quite tasty. They have a roped off swim and play area you can use, with various trampolines.
Read Medtech2's full Norwegian Sun cruise review
Norwegian Cruise Line