Yucatan Peninsula in Mexico is famous for its cenotes – sinkholes created by the collapse in limestone bedrock that forms the top layer of geology along the cost. The resulting fresh water filled reservoirs were used by Yucatec Maya (ts’onot in Mayan) for drawing water out of and throwing offerings, including humans back into.
In oceanography, a halocline (from Greek hals, halo- ‘salt’ and klinein ‘to slope’) is a subtype of chemocline caused by a strong, vertical salinity gradient within a body of water. Because salinity (in concert with temperature) affects the density of seawater, it can play a role in its vertical stratification. Increasing salinity by one kg/m3 results in an increase of seawater density of around 0.7 kg/m3. (Source & Links: Wikipedia).
Over 6000 cenotes in Yucatan form a fantastic underwater world of caves and caverns that is a joy to explore and the mixing of the salt and fresh water at depth that forms halocline layers gives the journeys a surreal, dreamy quality. Like floating in space above the surface of the Moon.
All out dives were with amazing http://phocea-mexico.
1) Preparing for the cenotes dive at Car Wash
The most famous ones are Grand Cenote, El Pit, Car wash and Dos Ojos each offering a different adventure – my favourite by far is Angelita
2) About to discover Angelita
With a diving depth of up to 55m, the little angel hides a magical underwater island rising from the swirling sulphide layer – while you descend through the milky cloud of sulphur the smell is quite strong and visibility reduced to backlit white out and then suddenly you are in the salty realms of deep waters (and the possibility of narcosis!). But it is going back up that is even more surreal: rising through the whiteness and the halocline layer you surface in the fresh water and it does feel like air – like floating above the surface of the moon.