This is a small area that's been taken care of for years; and, has a history of cave divers doing this small water area, with a death in the outcome. Check the history of it on the Internet. But, first read this ugly story of three guys who were feeling their oats and what's being offered for finding and turning them in.
http://www.msn.com/en-us/news/us/guns-b ... li=BBnb7Kz