That is typical of tours and resorts. These are not in the US where the law might investigate. Just some divers who will show anyone around. Many will teach you to dive, a two hour course is enough for a simple dive (ie.something you could snorkel to), then they take you on a first dive that needs far more training.
The issue that many take with PADI is that their values are mostly aligned with making profits.
> You need to be PADI Advanced Open Water Diver who is at least 18 years old to enroll in the Cavern Diver course.
After doing some research around this. Cenotes are an exception to the rule and even though Open Water Divers often do enter inner rooms in wreck dives and caverns what matters is maintaining a direct line of ascent.
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Open Water can do caverns. Dos Ojos is incredibly popular and has hard ceiling.
Edit: Also Cavern Diver is just a specialty cert and doesn't confer any extra penetration. Those certs are mostly designed for skill mastery. IANTD's Cavern cert is required to get Full Cave, but I don't know if PADI's would count towards it.
https://blog.padi.com/2019/04/29/must-dive-cenotes-for-open-...
> certified Open Water Divers can take a cavern tour guided by professionals qualified by some of the cave diver training organizations to lead such tours. This is a highly controlled, limited tour along a line into the cavern zone, which is defined as within the natural light zone and within 130 to 200 ft (39-60m) (some minor variations here) of the surface.
As a rule, they absolutely aren't.
In this specific place, PADI allows some of them to make a supervised dive at a certain site following a specially installed line. This doesn't change the rule, which is "Open Water Diver certification does not qualify you to dive on shipwrecks, nor caves".
At some other place, there may be an option for a person with Open Water certificate to drive a semi-trailer truck, while under supervision from a trained professional, and over a course specifically crafted to minimize any possible collision. This doesn't change the rule, which is "Open Water Diver certification does not qualify you to drive semi-trailer trucks."
Where I'm confused is the difference between a direct line of ascent (even when there is an overhead directly above) versus penetrating beyond that. This is a differentiator that makes swim-throughs OK but most caverns not OK.
Edit: Turns out I can't edit a comment that old.
What you describe sounds like a terrible and irresponsible trip to me.