Cave Diving

Yucatan Peninsula, Mexico
While there is great potential for cave diving in the continental karst throughout Mexico, the vast majority of cave diving in Mexico occurs in the Yucatán Peninsula. While there are thousands of deep pit cenotes throughout the Yucatán Peninsula including in the states of Yucatán and Campeche, the extensive sub-horizontal flooded cave networks for which the peninsula is known are essentially limited to a 10 km wide strip of the Caribbean coastline in the state of Quintana Roo extending south from Cancun to the area of Tulum and the Sian Ka'an Biosphere Reserve, although some short segments of underwater cave have been explored on the north-west coast (Yucatán State).
In the Yucatán Peninsula, any surface opening where groundwater can be reached is called cenote, which is a Spanish form of the Maya word d'zonot. The cave systems formed as normal caves underwater, but upper sections drained becoming air filled during past low sea levels. During this vadose, or air filled state, abundant speleothem deposits formed. The caves and the vadose speleothem were subsequently reflooded and became hydraulically reactivated as rising sea levels also raised the water table. These caves are therefore polygenetic, having experienced more than one cycle of formation below the water table. Polygenetic coastal cave systems with underwater speleothem are globally common, with notable examples being on the Balearic Islands (Mallorca, Menorca) of Spain, the islands of the Bahamas, Bermuda, Cuba, and many more.
As with all cave speleothems, the underwater speleothems in the Yucatán Peninsula are fragile. If a diver accidentally breaks off a stalactite from the ceiling or other speleothem formation, it will not reform as long as the cave is underwater so active cave conservation diving techniques are paramount.