Hi, Kateryna! As an Open water Diver, you are certified to dive in conditions and areas similar to what you have experienced...so, Open Water. Cenotes are, for the most part, Caverns. "Cavern diving is the exploration of permanent, naturally occurring overhead environments while remaining within sight of their entrances" They have a clear access to the surface, unlike a Cave. But, because of the objective dangers often found in Cenotes, they pose a higher level of risk than a dive in truly open-water areas. In my dives at Tulum and Gran Cenote, I joined with an experienced Cave-certified Guide...there were areas that were so crystal-clear that vertigo was a real danger, and some constricted areas that could be disconcerting to a diver not experienced with them. No, you do not "need" a special certification for Cenotes, but certainly make a self-assessment of your skill level and comfort in colder, potentially dark and confined areas and never dive without an experienced, trained and capable guide.
