I've been in Choc Maal, Tajmahal, and Dos Ojos with Sealife Divers. I am a tad bit claustrophobic, but had no problem. They only allow 4 divers per guide, and as I understand it the guides are all CAVE certified. I thought all of these dives were very beautiful, and am planning on doing my cavern specialty class when I'm there in February. By the way if your interested I do have some photos of the entrances and in the caverns that I can share with you. I would put them on a website, but I've never taken the effort to learn how. Be sure to wear a full wet suit. The water temp is fairly constant at 72 F and you will get cold on the second dive if you don't wear the proper exposure suit.