After visiting Chichen Itza and stopping for lunch we stopped off at the 60m deep cenote Ix Kil and went for a swim. Unlike many of the people there I did not have a water proof camera so my only two pics are from before my descent aand after.
I did get up the gumption to dive off that platform.
I have swim in water deeper than that in the ocean but it was a strange feeling to know that you were in a hole with nothing but water underneath you for almost 200 feet.