Cenote Plasma Torus
One of the things I like most about living in Mexico is the possibility of cave exploration. Not only do we have the biggest concentration of flooded caves in the world, but there are many more to be discovered. In early 2022 a new cenote was scouted by Tristan Ternat. He said that the cave continued and had some good exploration potential.
Discovery, cave exploration and connection
THE ENTRANCE — The cenote’s water was in a dry cave, entered by squeezing through a low entrance – about a metre of clearance and then the cave then opened up into a large dry gallery. This first gallery became our dressing room and gearing up space for our dives. Carefully walking down a rocky slope and to the left (as you look into the dry cave) you reach the surface pool, and on the far side of a dune of calcite rafting the underwater cave passage opens up. On the other side, to the right of our dressing room, the dry cave continues quite a bit further, maybe 100 metres before ending in a collapse. On this side, there is a second underwater cave entrance, with the cave extending north underwater.
Continuing the exploration
In a May 2022 exploration season, Phillip Lehman and I returned and continued to explore the cave. Initially, Tristan had laid a line in each of the water-filled sections from the dry cave. We dove into the closer, easier-access pool first on the south side. Tristan’s line went pretty directly south, through a shallow, decorated, white cave, for 300 feet (100 metres) before ending, with the cave tunnel continuing. We tied our reel into the end of Tristan’s line and continued southward until the cave got smaller and seemed to wall out. Being on CCRs meant that we could back-track along the line and try some of the leads, tunnels with exploration potential, that we had marked on the way in. This is exactly what we did, pushing a lead west before trying to turn back and head to the south. Each time we tried to go south the cave soon shut down, tunnels ended, or were becoming too small because they were filled up with sediment, or we found the way blocked by stalagmites and stalactites. We were forced to backtrack and go west again.
This was how the exploration seemed to go on those first dives. We continued to follow the trend of the cave, with tunnels extending south only to choke up with calcite rafting or wall out. Western tunnels ran for some distance before ending and then we would continue to try going south.
One day we took a break from the southern section to check the northern side. Diving the northern section the cave was just as shallow and if anything more choked up with calcite rafting and sediments. This made it hard to find a way on, and some line was laid before finding a going passage. The passage continued for a ways through low, calcite-filled tunnels before we found another line. Swimming down it, we came to one of our exploration arrows. We had connected the northern section with the southern!
Rebreathers: tools for exploration
Over five days of diving we extended the cave to 11,300 feet (3,400 metres). Much of this was made possible by us diving rebreathers and the advantages they gave us. With Close Circuit Rebreathers (CCRs) we were able to stay in the cave for many hours at a time. Less percolation also meant that we had good visibility for all of the dive and could check leads we had marked close to the entrance with still decent visibility by the end of the dive. We would not have had this on open circuit systems.
Cave connections
Plasma Torus had grown to 16,000 feet (4,870 metres) when we connected it to a neighbouring cave system. As seems typical for the area, the connection was made through an insignificant-looking restriction. We had been pushing a line to the north-west, and where we had ended it really seemed to shut down. The tunnels ended, and there was no way to work around the end of the cave. Working our way back along the line we had laid, we tried every side tunnel to see if there was any way to continue. We had done just that and ended our line when the tunnel seemed to end in a collapse when I saw a low, unpromising lead on our left as we swam out. I gave Phillip the ‘hold’ signal, tied in my reel and squeezed along, laying a line. I had to push up through a low breakdown where the roof had collapsed down, and then again on the other side. Once on the other side, I looked ahead and there was an end of a line in front of me! I connected the reel, then swam back to call Phillip to come see what was there.
We continued along this mystery line, wondering where it had come from and who had placed it in such a remote section of the cave, and reached the end. At the end of the line was a tie-off with an arrow with our names on it, the previous year’s date, and the name ‘wolf’. We could recognise where we were with that information! The line was the ‘wolf’ line, one we had cut back from the mainline creating a jump, as we thought it ended!
Future Exploration
So what’s next? Well, there are still many leads to push from both cenotes. There is a very clear trend that the cave is blocked to the northwest by collapse and breakdowns. I am optimistic that with enough time, we will be able to find a way on and break out in that direction. Hopefully, we will have the opportunity to return during 2023 for a few days diving in Plasma Torus and continue the exploration!
Filming the exploration
Kim Davidsson joined for two days of exploration. A few years ago, Kim, Phillip and I filmed an episode for Somos Los Cenotes during an exploration dive. This is always a bit risky. What if we don’t find any cave, we silt it out, or it’s small and doesn’t make for a good film? Luckily, on that dive, we did find some amazing cave, and each emptied a reel! So our hope was that we could repeat this again in Plasma Torus. And the cave co-operated with us! We made our way to the end of the line and took off, first me laying the line with Kim lighting up the cave and Phillip filming, then when I finished my reel Kim and I swapped roles. What a fantastic day that was!
Underwater photos by Phillip Lehman, above ground by Alfred Minnaar
Support as always by ProTec Dive Centers