In early 2024 a connection was made between two cave systems. This was significant, as these cave systems are (as far as we know) the most southern cave systems in the Riviera Maya (the zone from Cancun south to Tulum and Muyil). As they had been longish term projects of mine, it was incredibly satisfying to connect them. We knew from the cave data that they were close, and had previously made a number of dives to try to connect them but it hadn’t happened. And with the connection, it looks like this could be the beginning of more exploration!
History of the caves
Cueva de los Montes was first explored by Alvaro Roldan (who used to work at ProTec in Tulum and explored many caves in the Muyil area) in 2015. He made some dives there and then invited some friends. Jaime de la Puerta and Tamara May added a little more line to the cave. Then in 2018 looking for new cenotes in the area, I stumbled on this one, looking down into the water, I clearly saw a cave line. It was nice to find Alvaro’s arrow at the entrance and at least be able to identify who had been there before. To get a good understanding of how the cave was, I resurveyed the existing lines. In the process of these dives, and hiking around in the jungle, I was able to connect the cave to a few other small cenotes close by.
Bruce Lee was a cenote we discovered in 2018 when hiking the area, being on the same trail as Cueva de los Montes. Its cave diving potential was ignored until late 2019, because of its incredibly unpromising entrance. From looking at it, it appears the sediment has completely filled up the cenote leaving a shallow pool. At first, I had dismissed it as a dead cenote, one that was completely filled in and without any cave. It was only after doing more diving in Cueva de los Montes, and seeing where the cave was going, that I thought it might be worth trying to dive from Bruce Lee.
This name came from the difficulty of getting into the water - Bruce Lee’s mastery is considered legendary. You need to crawl on your belly through a restriction, in thirty centimeters of water, to reach an air dome where there is space and height to attach sidemount tanks, then try to swim (or reduce the amount of crawling) to the other side of the airdome to be able to descend into the cave.
I first scouted the cave in wetsuit, with 40 cubic foot tanks, not having any faith that the cenote would continue. But after dropping down into the cave, navigating some dark tannic sections and some restrictions I popped out into a big cave passage! Cutting the line and tying off the reel, I began surveying back out, I was excited with the prospect of a new exploration project!
Dominican Republic Speleological Society Dives
At the end of 2018 myself and Phillip Lehman from the Dominican Republic Speleological Society were doing some exploration in Muyil again. After doing a day in Cueva de los Montes and looking at some other potential entrances in the same area we decided to dedicate our time and effort to more promising prospects. But the cenotes we had found still needed diving and checking. So I went back and scouted and dove those entrances. There were six different entrances to dive. We had ignored them mainly because they were small and silty.
One of them required pushing my sidemount tanks into the water ahead of my body, and then leaning into the water face first while breathing from my reg and continuing to push the tanks in front until I had enough space to attach them to my body. Many of these entrances very quickly connected into the growing Sistema de los Montes. As these connected between lines, they just helped fill in the map, rather than open up any new area for exploration. One of the other cenotes had a short bit of cave that very quickly ended with no further exploration possible. The last cenote I checked turned out to be worth more dives, and so was subsequently named Chuck Norris.
With Montes growing, we also did a number of dives in Bruce Lee. I was still diving open circuit at that point, while I waited for my Sidewinder Closed Circuit Rebreather to be delivered (and my training). So over a few dives our team - Phillip and Patrick diving their KISS Sidewinder rebreathers, and me in open circuit continued the exploration. The cave we found was quite diverse with big, white rooms that then ended in breakdown collapses. Some sections of the cave shallowed up into tannic domes with heavy tannic acids, there the cave looked really eroded or dissolved away by the tannic acid. During this time many of the lines were named with a Kung Fu theme. With some quite small restrictions on the way to continued exploration we again left the project in favor of ‘easier’ caves to continue exploration in.
Covid 19 Pandemic Dives During Lockdown
In March 2020, I was back in Australia visiting friends and family; at that time, as many remember, there were a lot of news reports starting to come out about COVID. Especially when things started to go bad in Italy and France. I made the decision to cut short my time in Australia and get back home to Mexico in case things started to shut down or travel was restricted. Turns out this was a very lucky choice, the day after I left Australia, the government closed their borders!
With all the restrictions on travel, and the local suggestions to stay home and for public businesses and cenotes being closed, there was suddenly a lot of time on our hands. So Bruce Lee became a focus for our exploration efforts as it was out in the jungle and very easy to social distance ourselves from other people! Myself, Patrick Widmann, Jake Bulman, Jaime de la Puerta and Kim Davidsson all were part of the effort to continue the exploration of Bruce Lee. The explored section of the cave continued to grow slowly, finding the way forward was difficult.
On one dive, Patrick and I were trying to find the way for most of the dive. I was on open circuit with a stage tank. I was close to turning the dive, nearly at my gas limits. Right at this point, I pushed through a small, unlikely restriction and boom the cave opened up into a well defined tunnel. I reluctantly gave Patrick the signal to turn the dive, and mimed that I was crying. Patrick, rather than accepting this, communicated that we could swap our right sidemount tanks and continue a little bit further on. We managed this quite well, passing off and receiving the right tank, donning them again and then continued. While this was unconventional, it was still totally safe, with Patrick having plenty of bailout gas in his tanks (average 150 bar across both) and I used my ‘fresh’ tank quite conservatively (while leaving my left tank untouched from that point, and having another tank staged on the way to the entrance). We finished off the reel, completed the survey and headed for home.
Close Circuit Rebreathers and Scooters
As the distance to ends of the lines became further and further from the entrance we began to use DPVs and CCR to have more time to explore. By this point I had crossed over to the Sidewinder CCR, built up quite some experience on it, and was comfortable taking it into these smaller caves. Once it became about an hour of swimming (or around a kilometer / 3000 feet) just to reach the section of cave where we wanted to explore it started to make sense to bring DPVs. Even when using our Seacrafts on low speeds, it is still faster than swimming and more efficient for gas use (or reduces CO2 output if diving rebreathers).
As we pushed the exploration lines north east we crossed under the highway. Suddenly things were looking interesting. We had explored another cenote close by and thought we could connect the two, which would have made Cenote Bruce Lee into Sistema Bruce Lee (a cave system needs to have more than one entrance). This cenote had been dove by Jake Bulman with support from myself and Elliot Smith. It was more of a solution tube or well, which Jake climbed into with a rope ladder and then we lowered tanks down to him. He had put a bit of line into the cave, and looking at the data Bruce Lee’s lines were headed in that direction. So our focus was to push the cave in that direction.
Using rebreathers for exploration has some advantages over open circuit scuba systems. We were able to stay longer, as our gas supplies were not used up, which meant we could attempt various tunnels to try to find where the cave continued. On open circuit SCUBA we would have had one or two attempts before needing to return due to gas pressures. Given that we were not producing many bubbles, the visibility in the cave stays relatively good as there is much less percolation (silt raining down from the ceiling) compared to open circuit. This is very helpful when doing longer dives as it means we can continue to explore new passages with decent visibility.
Chasing the Connection
On another dive, myself and Jaime de la Puerta entered from Cueva de los Montes with the idea to connect the two systems. We headed north-west from the Montes entrance, a small pool in a shallow depression. There was just enough room for one diver to stand, and don their sidemount tanks and descend. The first diver then has to wait at the bottom of the slope for the second diver to climb into the pool, put on their tanks and then meet up at the bottom of the slope. We both entered the cave one by one, and then met up at the T-intersection at the bottom of the slope.
Once we swam about thirty minutes into the cave we were able to start checking for any leads going north or northwest. At this point the caves were fifty meters apart at some points, so any little distance closer was a good thing! On that dive we noticed a few leads and added a bit of line but nothing seemed to be going, one of the lines looped back, and the other two walled out. So after surveying the line we had laid with the Mnemo survey tool, we turned back to the entrance. Sometimes it makes more sense to review the data and see where the lines go, before trying again to continue the exploration.
On the way back, close to the entrance, I noticed a little duck under. We still had time, gas, and line so communicated that we would try it. This line actually was more successful, and went in a north direction. Unfortunately soon enough we encountered a restriction that would have required removing both our tanks, and here we decided we had done enough for one day.
After hiking out of the jungle, eating the roast chicken we had bought on the way to Muyil and rehydrating, we started to put in the data. Immediately we saw that one of our lines was now only 20 meters away from the lines of Bruce Lee! While another was 45 meters away. These would be the next points to really try to push from! All in all it was a very successful day, and a lot of fun. The two cave systems were closer, and Montes had grown in size by nearly 500 meters (1500 feet)!
And yet, still no connection, despite some returns to Montes to explore the cave in the other direction (away from Bruce Lee). Other exploration projects again held more interest and diverted my time until finally in early 2024, Phillip Lehman and I decided to return to Montes and had another look both south and north west towards Bruce Lee. We didn't have much luck pushing hard on the southern lines, what we had done previously seemed to all wall out on a second round of checking. Heading towards Bruce Lee, the line which was the closest definitely could not continue as it was solid rock on all sides.
Off the end of Jaime and my old line we tied in and started down a lead. A short distance along, the cave narrowed down to a restriction. I gave the hold signal, and removed a tank to squeeze through, deploying line and making tie-offs. It didn’t look promising but I continued on, and amazingly, the cave started to open up. There were sections of flow ripples along the floor, pointing to water moving through this tunnel. Not long after, the cave widened and right there in front of me was a cave line!
I connected in, cut away the reel and attached an arrow to the newly created T-intersection. I surveyed the new line back until I met up with Phillip and called out the good news to him through my rebreather loop "it connects, one system!". We fist bumped and then began the swim out, our planned ‘shorter, chilled’ dive ending up being over 5 hours long! Back on the computer in Tulum, the data did indeed confirm the connection! Because Bruce Lee had the greater length this became the system name and the overall length was now 6,500 meters (21,500 feet).
These explorations hold a special place in my heart because of the people I shared the dives with. While it is not a very long cave system, being in the team for pretty much every dive there (apart from the early exploration) meant I was involved in most of the exploration. Some of the exploration was quite challenging, small caves, restrictions, low visibility which in part led to the title of this article! Always optimistic, I still think there is more cave to be found there, and future dives have already been planned!
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Photos by Alvaro Herrero aka Mekanphotography
Written by Skanda Coffield-Feith
Skanda Coffield-Feith is a cave and rebreather diving instructor, and cave explorer. He is based in Tulum, Mexico; ten minutes drive from the world's longest underwater cave systems. Originally from Melbourne, Australia, he learned to dive in Koh Tao, Thailand in 2006 and was immediately hooked. He spent some years diving in some of the best locations around South East Asia as a recreational diver, before discovering that he could dive in Melbourne. Diving in Melbourne he was introduced to technical diving and heard about cave diving. During a trip to Mount Gambier, he was introduced to the famous Australian caves and became a cave diver. Skanda now spends most of his time teaching at ProTec Dive Centers Tulum. His focus is on training divers in cave diving specialty courses like cave survey and stage cave, as well as teaching the KISS Sidewinder Closed Circuit Rebreather. When he is not teaching, he is out in the jungle exploring new cave systems. While predominantly involved in remarkable exploration projects in Mexico, he has been a part of cave exploration expedition in Australia.
