I am one of those instructors who has permission to dive there. I will be there July 21-24 and August 6-7. I will be teaching classes both times. I am not opposed to having others join me if I am confident things will be OK (description of OK below). I will have at least one other diver joining me in July.
Rock Lake is a sink hole in the prairie with almost nothing in the way of accommodations in the area. There is a small tin shed, a picnic table, a table for setting up gear, and steps leading to the water. That's it. I will be bringing a groover for the first time this next trip--before that (and for about everyone else), using the rest room means squatting behind some piles of brush.
The lake is about 400 feet across east/west and 500 feet north/south at the surface. I have no idea how big it is at the bottom--I just know it is bigger than that. At the south end, the lake is 200 feet deep, and it goes to about 285 at the most--maybe. I don't think the bottom has really been mapped, so I don't think anyone can be sure of having been to the deepest point. When we dive, we stay near the walls so we have a visual reference, and going all the way to the bottom is actually a pretty rare event among the divers I know.
The walls are layers of sandstone with some clay lines, and it is all covered in what I assume is
goethite, giving it a purple/black color and an interesting texture. Like most sink holes, the lake has something of an hourglass structure. The top level slopes toward the middle of the lake until a depth of about 30 feet, varying by location, after which it plunges to the abyss, with most sides undercut to form a larger area below. The shoreline is mostly reeds, and the top level of the lake has water plants with very fine leaves. These hang down over the cliff edges, making me think of the hanging gardens of Babylon. When those very fine leaves die, they break off and fall like fine, gentle beige snow, leaving piles of powdery silt on the rock ledges below. On some of those ledges, selenite gypsum crystals emerge, with a coating of goethite. (See the goethite link above for a picture of such a formation.) I think it is a beautiful dive sites, and I never tire of diving it.
So what makes you OK to join in the diving there? the owner requires that all divers be adults with at least AOW. The instructor supervising the scene (in this case me) has a lot of responsibility to make sure everything is cool--no one gets hurt, and the pristine nature of the area is maintained. The owner is, frankly, skittish about the whole thing, and she could cut off all diving in the blink of an eye. That would eliminate just about the only decent tech site in the Rocky Mountain region. Once when I was with another group under another instructor, he let some people he did not know join us. They dived on their own and left OK themselves, but on one of our dives, we found a deep hand print on one of the shelves with the fragile crystal formations. He said he would never let anyone back that he did not know.
I am more willing to admit people I don't know if we have good communication about skills, experience, and a total commitment to maintaining the ecology of the site. In fact, I encourage it. There are not a lot of people using the site these days, and it is hard to get buddies, etc. I would be happy to build up a core of responsible people who dive there. I would be especially happy to attract more trimix-certified divers to share the cost of helium and provide a buddy for the deeper dives.
Let me know if you are interested.
