It may have been some other type of Ray, I'm just guessing, someone else near the water called it a Sting Ray too. Today in Miami beach I saw it. I had never seen one before. It was a little over a foot wide and was dark with light colored spots. Luckily the water was cold so I had only gone in to my knees when in swam by. It was pretty quick too. I also saw my first Jellyfish today, it was about the size of a dinner plate.