It is a stingray (not sure what kind)! And the other is a cobia. We were pretty deep, so had a bit of a slow shutter (even with an external flash) and the pair of them whipped around as I clicked the shutter button.
Wierdest thing I ever saw, these 2 were paired up, the cobia swam directly above the ray everywhere it went. Awful strange pairing. Here's another shot.
Also, this was a cool pic I snapped that same dive, different ray.