Dive Aventuras is a great shop, well established with a good reputation. Do a couple ocean dives with them before the cenotes. They'll know your skill and comfort level and if you want to do a cenote, they won't steer you wrong or get you into something you can't enjoy and manage.Thanks for your replies. It sounds that the cenote dives are real cave dives - no place to surface any time, and it could get very dark - both of which I'm not qualified for. If that's the case for all cenote dives in the area, is "Dive Aventuras" very irrsponsible and very misleading by stating that "Although special certification is required for divers who want to penetrate caves, no advanced training is necessary for certified divers who want to explore the cenotes, since routes always follow tunnels bathed in natural sunlight" ? If they are, why everybody on this board seems to be raving about this operator? Could there be some particular dives that fit their description?
Technically, the "cavern zone" is within I think 250ft of an exit, and daylight. And yes, there is no cert other than open water needed to do a cenote dive with a qualified guide within the cavern zone.