Coka Ha East
Cenote Coka Ha was originally found and explored by Bil Phillips in the early 2000s and it belongs to the Ox Bel Ha cave system. This part of the cave system is characterized by mainly huge freshwater tunnels, dark cave decorations and lots of percolation. In 2019, right at Coka Ha, cave divers Gideon Liew and Laszlo Cseh resurveyed a massive, but very defined passage going straight towards the east with a decent amount of flow. After a lot of unsuccessful attempts breaking out either to the north or south of this tunnel, towards the end of line the team took a southeast turn following the water. This led to the discovery of 2 new cenotes (later named: Muuch and Ookol) and a few open leads.
The team was still thinking about further possibilities from the new cenotes to the east, but losing access to the Coka Ha area made things more complicated. After finishing some other projects, the divers had time to return here in 2022, but their point of entry became cenote Chuup Ich, about 2,6 km north of Coka Ha. This added a considerable amount of additional travel, not counting the entirety of the east tunnel next to Coka Ha. After checking survey data and making some calculations the divers have identified the current end of line being at 4,1 km from Chuup Ich. Preparing with special batteries for the DPVs and having enough experience and knowledge about the area, the team decided to initiate regular longer dives downstream from cenote Chuup Ich.
Cenote Chuup Ich entrance
Although being fully overhead, luckily 90% of the travel was comfortable, with quite some navigational points and a few restrictions along the way. The team encountered one major restriction at a penetration distance of 3,6 km, but a bypass tunnel was found nearby which was slightly easier to navigate. On the first dives already the divers made good progress in pushing the cave further to the east, hugging the east wall of the cenotes and dropping a bit deeper. After some irregular and smaller silty tunnels the cave opened back again into it's regular size, was full with dark decorations and the east water flow picked up again. Unfortunately this lasted only for a couple of hundred meters when the cave hit a high silty slope with organic sediment. Swimming on top, a small dry cave has been found with lots of bats inside and a small source of light on the opposite wall. The divers named this little room the bat cave for future reference.
The cave past Cenote Coka Ha
Descending back from the Bat Cave
Initially it seemed there was no way around the bat cave. On a subsequent dive a dropdown to the northeast next to the bat cave was discovered and the divers continued in that direction. The expectation was that this tunnel hopefully will loop around the bat cave, ascends a bit shallower and continues going east. Once the cave took a northeast direction, the ceiling descended at the same time and percolation was following us even more aggressively. The challenge in this area was to work as fast and efficiently as possible since there were only moments of visibility available for the lead diver. If one lead wasn't identified well, or took too long to check, we were looking at another 4,5 km travel for our next dive. Little by little the team made good progress but the cave never returned to its original depth and direction.
The cave was pushed further from this point in multiple directions, but all of the leads became increasingly smaller or ended in a collapse. Close to 5 km of distance from our original point of entrance this area of the cave seemed to end. On the last dives closer leads have been checked, but after a while neither of those wanted to leave the main east direction too much either, they must have been created just as a side effect of the massive water flowing straight to the east.
The total new exploration distance in the area was : 3200 meters / 10500 feet with the biggest new coherent area being 2100 meters / 7000 feet. Avg. depth: 11 m / 36 feet, max. depth: 19.5 m / 64 feet. The team has used open circuit GUE backmount and sidemount configuration with multiple stages and SUEX DPVs.
Longest penetration: 5 km / 3.1 miles
Average bottom times were: 6-7 hours with minimum decompression
The dive team consisted of: Emőke Wagner, Bjarne Knudsen and Laszlo Cseh