Return to Corazón

by | Jan 3, 2022 | Exploration

Earlier this year I happened to be guiding a former student in Corazón del Paraíso. It was awesome to be back diving in that cave! Big tunnels really cool flowing haloclines, interesting decorations, and small silty passages. The cave is really varied! Being back there made me think there might have been some unfinished exploration. Many of the lines I laid there in 2018 were done on open circuit, now with the rebreather the potential to find more cave or even a connection was there!

The 2018 explorations

Back in 2018 after resurveying the existing cave lines (everything up stream and 1000m / 3000ft downstream) I found some new passages. Many of these didn’t go very far, but some I added in the salt water did go some distance. In total I managed to add around 3,500 feet of new line. Much of the exploration was done in pretty silty conditions, because as soon as I would exhale, percolation would cascade down. This meant that I only would have one chance to pick a direction before zero visibility closed in. Many of the ends of my lines were left with comments like ‘could go, small and silty’. So a return was not high in the priority list! At the end of 2019 I did return with Tamara May and we explored another 500 feet of challenging salt-water passages. But again nothing was significantly going, lots of silt and breakdowns to navigate.

Chasing the Santa Maria connection

One of the longer sections I added did seem to be going in an interesting direction. It was parallel to the main tunnel, and had similar conditions. But outside of the existing lines, meaning this could be where there is a chance to break out of the tunnel into new cave. Fast-forward to 2020 and we had extended the existing lines of Cenote Santa Maria and added 4,000 feet of line pretty much in one direction downstream. Right towards the upstream ends of line of Corazón, and most importantly my line! I remembered that there was potential unexplored cave off that line; it was just very, very silty! Knowing that there was more cave to north, with quite some flow coming towards Corazón, it was time to try again.

CCRs, the game changer

Recently Tamara Adame and I went back to scout out the tunnel and check leads. Pushing a low silty bedding plane, I popped out into a big open room with options on where to go! Tamara followed through, and I passed off the reel to her and went back and began to survey in. Tamara laid some line down into a saltwater passage, but diving open circuit this was pretty much zero visibility for me surveying in behind her. Once we came back from that line, it was time to turn on gas, but there was definitely more cave off the initial big room. It was time to go back with just rebreathers!

I returned with another friend, Marceline, and we extended the line that Tamara and I had laid a little bit before the cave shut down. It seems fairly typical in this section of cave that once in the salt water, the passages are shorter and tend to end in breakdowns. The floors in the area are pretty silty, and even being on CCR there is a lot of percolation. We continued along my 2018 line and checked out some of the other leads I had noticed. Having the luxury of no time pressure with the rebreather gave us a chance to check a bunch of leads, and reduced the amount of sediment stirred up by bubbles.

While none of these leads were really going cave, they did not continue far or open into bigger passages, we did manage to lay a bunch more line and connect some of the lines we laid to existing lines. While not really significant or useful connections, this does help with confirming the accuracy of the survey. Knowing that the survey is accurate will help with the eventual connection to Santa Maria!

This summer has been a pretty busy time for us at ProTec with lots of teaching and guiding. With my teaching and guiding workload, and other exploration and survey projects I only managed a couple more dives continuing the exploration. During one of these dives I pushed one lead I had noticed with Marceline and the cave opened up! At least for a little bit! The passage dropped again into salt water with flowing freshwater on top. Soon enough I found myself in zero visibility and had to turn the dive. But there seemed to be potentially some more cave to explore in that section.

Another day I went back to check some of my ends of line from 2018. On my survey notes from back then there was the comment ‘cave goes small’. Probably why I never went back! But not wanting to leave any possibility unchecked, with the sidewinder it was time to go back! One of the lines continued through a snakey, zigzag tunnel which didn’t really go the direction I wanted to push. The other line dipped in and out of saltwater before I popped up in a surprisingly big room. Looking around the walls for a way on, I checked the directions I wanted to push. But nothing, then turning back towards where I had come I saw a lead off to my left. Swimming over to it unfortunately I saw that disturbed sediment had already drifted into the potential way on. Deciding that exploration in clear water is way more effective, efficient and safe, I cut free my reel, tied off the line and began to survey out. 

Since the last dive I have been pretty booked up teaching so haven’t been able to go back. But one of these days when I have a spare day or two it’s going to be time to build the sidewinder, charge the Seacraft and Mnemo survey device, feel the exploration reel and go back!