The Yucatan Peninsula

The Yucatan Peninsula in southeastern Mexico is a popular tourism destination and widely known for diving along its gorgeous Caribbean coast line. Less well known are two other destinations for divers and snorkelers.

Cenotes

The entire Yucatan Peninsula is a flat lying karst landscape. This limestone-based rock has enabled the formation of Cenotes which are pits or sinkholes. Over 6000 cenotes exist. They are surface connections to underground water bodies (caves). The Yucatan is crisscrossed by hundreds of kilometers of flooded cave systems.

When descending into a cenote, the border between fresh and saline water may be reached. This crossing point is called halocline, which means a sharp change in salt concentration over a small change in depth. Mixing the two results in blurry vision when you pass through it due to the different densities – an awesome effect to be witnessed. The closer to the coast, the shallower the halocline is.

Some Cenotes have sulfide clouds at deeper depths giving the appearance of an eerie milky bottom when you descend.

Cave diving requires special equipment and certification. However, many cenotes are cavern structures and can be dived without cave certification.

Whale sharks

Every year during July and August hundreds of whale sharks congregate around the northern tip of the Yucatan peninsula. These massive fish come there to feed. It is possible to swim with them. Main points of departure are Isla Mujeres and Holbox.  Speed boats take you out in the morning for a couple of hours of magical interaction with these imposing but docile animals. Only snorkeling is allowed and no flash photography.