I did see a rest room, but I didn't check it out. As far as air fills and the such, there is nothing at all. Definitely bring everything you need. There isn’t a changing room either. As a side note, I did notice that the cave divers built them selves a cool gear up rack and shed to get out of the weather, but it’s not located convenient to the main quarry.
The guy that runs the place does check for C-cards.
He told me that there were no overhead environments that one could accidentally swim into, but I think that there are at least some cavern like areas. It was a bright day when we where there, so if it started looking kinda dark, we just turned toward the light. We made it about ½ way around the quarry.
Also, I would recommend gearing up on top by the steel steps. There is one picnic table that we used. It wasn’t hard to descend the ladder with our gear on. At the bottom is a small level area with another ladder that goes down into the water. It’s easy to get back up also.
It’s an extremely beautiful place.
Steve