The species is Bathytoshia brevicaudata, formerly known as Dasyatis brevicaudata. These rays, also called smooth or shorttail stingrays, are often attracted to places where fishos clean their fish. Sometimes you will see one without a tail, where some cruel person has caught the ray and chopped off the tail, in a misguided attempt to 'save the world' from the poor ray. These rays are not aggressive, but are very inquisitive. Treat with caution and don't threaten or frighten the ray and you can have a close encounter with a large marine creature.