Chuup Ich or "swollen eye" is located in the heart of the Ox Bel Ha cave system, but mostly it is known today as Cenote Corazon, renamed by the landowners who made the place public for swimming, snorkeling and diving in 2018.
It was first explored in 2003 by Bil Phillips and Steve Bogaerts. This area was our focus for our first exploration efforts.
In 2018 some dives have already been conducted here but systematic survey and the search for potentially new cave started in early 2019. The cenote is an in-line sink which separates the upstream and downstream section of the cave. The upstream part of the cave is much smaller compared to the downstream which eventually connects into other areas of Ox Bel Ha. The upstream is characterized by big open, dark tunnels, which are solid, but become smaller and smaller the further upstream divers travel. The mainline goes through some shallower decorated rooms, which are also colored black and dark brown, but sometimes on the side tunnels can be found which drop under the halocline, the color of the cave is brighter here but has much more sediment. The saltwater side tunnels are generally small in this part of the system. Closer to the entrance these smaller saltwater tunnels are connecting the upstream together with the downstream inside the cave. The downstream part of the cave has decent flow, is equally big as the start of the upstream and has dark rooms and sediment. Percolation further increases the more downstream the divers are getting in the cave.
Our first efforts to find cave here were pretty unfruitful since without proper knowledge of the existing lines plus the difficulty of having massive dark rooms in combination with heavy silting made us constantly bump into other lines or the opposite wall. Although it seemed a lot of work we have decided to resurvey all the existing lines for both upstream and downstream and make our way gradually deeper into the system and look for possible leads along the way. Relatively early the downstream part of the cave started to become more and more interesting, as we observed that instead of having a solid wall on the northeast side of the main tunnel there was rather a set of collapses. This led us to the assumption that the other side of the collapse might hides more cave. Since the mainline was in place already we tried to go out to the north systematically as we moved south. One opportunity seemed promising and has led to our first decent coherent exploration with about 1,5 kms / 4900 feet of new line. Under a ledge where the freshwater hit the halocline Emőke went out to find a relatively big freshwater room hidden behind that ledge. Hugging the new wall and going to the west the new tunnel seemed to end, but actually a deeper restriction allowed passage to continue the tunnel to the north but now under the halocline in the saltwater. After the restriction divers can find the biggest saltwater room in this area of the cave which also ended after another 100 meters. On the way out an even deeper ledge has been found, going from 20 meters to 24 meters which required sidemount equipment for a subsequent dive. The new deep sidemount tunnel had multiple holes on it's ceiling which led to other new saltwater rooms and tunnels in the area, but many of them were difficult to access because of percolation and the restrictions that divide them. After a few dives in the area all possibilities have been checked and soon this new corner of the cave seemed fully explored. We were hoping to travel further N, but the characteristic "collapse wall" along the mainline continued here as well and stopped the cave from progressing further.
After this effort the team continued with the survey and smaller new lines along the way as they moved downstream. The next breakthrough happened around a cenote called Kristen.
A good way downstream into the system the cave arrives to a bigger but shallow tannic dome. Even during the winter time in Mexico when we have less precipitation this room is still colored brown and makes exploration challenging. Luckily heading into this tannic room the cave drops slightly deeper and a tunnel reveals itself.
Cave divers Laszlo and Bjarne were trying to break into the west side of the collapse without luck. The cave became smaller and the silt increased when they ultimately looped back to an older existing line. On the way back, swimming deeper down between two rocks a dark tunnel has been seen with a decent amount of flow.
A few days later Emőke and Laszlo returned to check the lead which opened up into a new area of the cave which kept going for a good 700 meters of distance on the first dive to the northwest. Although the opening to enter this area wasn't big the divers were greeted with a massive sized main tunnel with some possibilities on the sides. Mainly freshwater was found here which is always a good sign. Towards the end the main tunnel split into 3 directions: one of the tunnels became smaller and smaller while the amount of fluffy organic-like sediment increased, the west side ended in a collapsed tannic room and the middle kept going for a while until it forced the divers to drop down to small, low-ceiling saltwater tunnels with extreme amount of percolation. This area of the cave resulted in a total new coherent exploration of 3,5 kms / 11500 feet.
The team moved further south and continued with smaller explorations and more resurvey until reaching the Coka Ha - Ayim intersection. Going towards cenote Ayim the divers resurveyed almost until the point of cenote Akalche where later another project has been started. East of cenote Coka Ha there was no data available for what exactly Bil Phillips was originally looking for which made the area interesting. Within the boundaries of another MCEP project Laszlo with GUE tech instructor and cave diver Gideon Liew resurveyed the above mentioned line, which started big, becoming increasingly smaller and irregular but the existing flow was steady. As the silt followed the divers survey it became more and more difficult to look around for leads, but since Bil's markers never changed direction it gave hope for continuing his line. As the silt in combination with the flow took a turn, the divers decided to follow the silt rather than the old line. A few 10 meters away they discovered two new cenotes, one which housed very tannic water and the other was crystal clear, so most likely this was where the water was moving.
The total new exploration distance in the area was: 8200 meters / 27000 feet, avg. depth: 15 meters / 50 feet, max depth: 24.3 meters / 80 feet. The teams have used GUE backmount and sidemount configuration with multiple stages and SUEX DPVs. Many thanks to all the great divers who contributed to diving with us in the area: Bjarne Knudsen, Dr. Mario Valotta, Zsolt Szilágyi, Gideon Liew, Peter Zirkov and Julian Eynon.