I called RPR and got some information. You have to be either a certified instructor or with one that has current insurance. I called RPR and they said some dive shops have open invites to join them if they have a class. (I know Aqua Trek did this at least once.) They named Scuba Land Adventures in Austin as a shop that goes there every week. I called SLA and they DON’T allow you to join them when they have classes. Scuba Land says they have a dive buddy club and they sometimes have events that are open invite to dive for fun. I signed up for the email notification list when they have events. This SLA buddy club costs $45 to join. (But has a few other benefits like a t-shirt, discounts, and free air fills for events.) And for all I know I’ll have to join SLA’s dive buddy club to be allowed to dive this quarry with SLA. Adding the $20 park fee and it comes to $65 to spend one day there. RPR also said if I call them with a specific date I will be there they will tell me who’s going and how to contact them to see if they will let me go. The bottom is RPR couldn’t really answer my question on how to find a group to join to just go and dive it. They don’t make it easy to visit just to dive it for fun.