Kevin is right in that the cave was opened up, and the people who opened it went in. There was a lot of confusion about this. They had apparently been communicating with someone in the local government and had gotten permission to do so, but that person then retired, not having told the mayor of the permission. The mayor was furious and demanded that it be closed again. The difference is that when it was closed before, the army corps of engineers did it with a couple dump trucks of rocks. Now that the rocks have been removed, there is only a grate, and that grate can be opened should such a decision be made.
Anyway, that's what I was told.
Only a short hop away from there is another sink hole, Rock Lake. It is much both much, much larger in diameter than the Blue Hole, and much, much deeper (about 300 feet). It is where most technical training takes place. It is on private property, though, and you can only dive it when accompanied by one of the technical instructors who has been authorized to go there. I love it myself, and go there a number of times per year. I will be teaching a technical class there this coming Monday and Tuesday.
I don't just instruct there. I am open to hosting qualified divers (you don't have to be tech) at the site under the right conditions. In fact, I am often looking for qualified people who just want to dive and (especially) share costs of helium, etc. It is hard to find people who are qualified to go to the bottom, and I am not into doing it solo, so finding a buddy is a plus.
Oh, by the way, the OP of this thread, amascuba, is now cave certified, but he has moved farther away and does not get there often any more.