Obviously, you've never been in the Ginnie Basin or the Ballroom. We've had 60+ people in the Ball Room on a galaxy dive (no lights) and have yet to see it get silted out. That's why they let OW divers in there. It's pretty sanitized for non-cavers.I can' believe your not worried someone might silt out the basin, get a student turned around, and they head into the cave to die. Sounds like the makings of a 40 page A&I thread.