I thought I made a post on this but cannot find it. On my last trip to Cozumel, I was able to make an eagle ray dive north of town. We drop down to 80-85' where there are some crevasses at the edge of the reef. Settle to the bottom and wait a bit until you start seeing glimpses moving south from the north.
First one, then another...and more. Finally around 15 eagle rays are moving effortlessly and gracefully. They disperse at some point but we wait a bit more and they soon come back. This time they glide over the top of us. This is one picture taken by Jim Duprie.