Seriously? Since when?
My husband and I dove there a lot before our cave certifications and the entrance signs and Janet (ranger) never required an instructor.
Miranda
I believe that what the entrance sign says. I never went there before I was overhead trained so never paid attention to the specifics. I'm not sure it's a heavily enforced rule, but I've never seen OW divers without an instructor there either. Oh, and Janet is no longer there.