November 2004

The network of caves is over 50 km long, forming complex mazes in karst (rinsed in limestone). The system is also unique due to fresh water wells dotted around the caves, known as the cenotes. Here and there, haloclines can also be observed, where the salinity increases and makes the water appear almost 'oily'. It impairs visibility, but the effect is quite stunning. Water in the caves is incredibly clean and, at around 26 Centigrade warm. An amazing variety of formations – underwater stalactites, stalagmites, draperies – create a fairytale world.

We have spent quite a lot of time in those caves, before any idea of beating the record came up. During that time, we tried to learn as much as possible about the huge network of Dos Ojos and Ponderosa corridors. We had to work it out, mapping it by ourselves, so as to not get lost in the labyrinth. You could even say that, in some way, we were true explorers. In many places we were the first divers, who came to these places. The idea of later record-breaking came from those original expeditions. In preparations for the record dive an idea to use DPVs appeared. They have not been used in cave diving before, being used rather by specialised army forces to transport combat divers.

We have spent these initial trips getting to know the routes and testing the equipment that was later to be used for the long dives in the caves. And even though in later expeditions we managed to set new records in cave diving, this possibility to explore, to discover something new, was most valuable to us as divers.