Category — Cave Survey

When we talk about cave diving, we usually refer to diving upstream or downstream. Upstream and downstream refer to the commonly accepted direction of the flow of the fresh water in the cave system. Here in Mexico, that direction is from inland to the sea traveling perpendicular to the coast. That knowledge is so ingrained locally that the government includes it in its planning documentation. If you take a look at the image (Click it.) of the slide, you will notice red arrows pointing to the coast. The arrows represent the government's official position on the flow of water around/under Tulum. It is also important to note that there are two versions of the urban planning documents issued by the local government. One issued in 2005 and one in 2007. If you look closely at the 2007 map you will notice the government has included stick maps of the local cave systems. This is a promising sign, the government is starting to incorporate cave survey data.

The problem is there is no empirical evidence to support the current common belief. There is anecdotal evidence that would support those hypothesizes, however it seems it may be incorrect.

On Friday night, Allie and I had the opportunity to go to Akumal and watch a handful of presentations given at the Centro Ecologico Akumal. There were a number of very interesting presentations, including: one on the dry caves of the area, one on the benefits of GIS, the formation of the local caves and one on the movement of water at Car Wash.

The talk about Yucatan cave hydrology and geochemistry was given by Patricia Beddows, a Research Fellow at McMaster University in Hamilton, ON, Canada. Patricia has been traveling to Mexico to study the caves for at least 10 years. Last year she and a team of volunteers performed a dye tracing experiment at Car Wash to determine the flow of the fresh water there. I believe the results are remarkable.

Before I go any further, she has so far performed one dye trace at this particular site Car Wash. Therefore, the results she shared can only be representative of the water flow conditions in the cave at that time. She mentioned that repeat dye tracing may show somewhat different results.

The experiment consisted of deploying two markers. She deployed one dye in the Cell Block section and at Cenote Luke’s Hope (Cenote Zacil Ha). Both sections are upstream or inland. The expected result was that both dyes would be detected at Cenote Carwash. However, what actually happened was quite startling. The dye that was deployed in the Cell Block section, just stayed there. It never really passed the restriction heading downstream towards the coast. So it would seem that at the time of the experiment, the water was not flowing from upstream to downstream as we all believe it does.

The dye that was released at Luke’s Hope also did something remarkable. It moved relatively quickly down to Cenote Carwash, this was expected. It also moved into the Room of Tears section, this was not expected.

It seems that the fresh water is not moving from upstream to downstream at Carwash. The new hypothesis is the water is entering the system from a perpendicular path from the North and then moving down stream and out of the system south. It is also blowing water into the Room of Tears section.

This is import for a couple of reasons. The first is resource planning. If the government assumes the water is moving from inland to the sea in a straight line, they will plan things like dumps and well fields accordingly. However, if the reality is the water is moving unpredictably; then there is a chance those plans will create a public hazard, such as contaminated drinking water.

The second reason it is import is, it means you and I are using the wrong terminology. There was some discussion at dinner about changing from talking about upstream and downstream to inland and coastal sides of the system. We wouldn’t want to be inaccurate when briefing our dives, right! You know how important it is to be accurate in your briefings, don’t you? So get out of the nineties and your halogen lights and into modern times, it will be Costal and Inland from now on.

Lastly, the term upstream gives the impression that the flow will be working with you to assist you in exiting. When in reality, it may be working against you as the finding suggests. For example, when exiting Room of Tears. I bet you never considered that the Room of Tears might be a siphon. A very weak siphon, but a siphon. I can think of at least one place in Nohoch where there is a strong current against you when exiting, where common knowledge would indicate there shouldn’t be water moving against you.

Naturally, you should now ask, “Why isn’t the fresh water moving the direction of the cave?” The answer is equally interesting. In the last million and a half years or so, the sea level has dropped substantially from today’s levels at least 3 times. It was during one of these low periods that the cave system was formed. No one is really sure during which low period the caves formed. Therefore, the caves were formed during a period that had significantly different geomorphic forces at work then are at work today. When the cave was formed, the water did move in the direction of the cave. It was the eroding force that formed the cave.

Today, sea levels are much higher and the caves are full of water. The movement of water beneath the ground on the Yucatan is controlled by: the tides, the macro geologic formations and hydrostatic pressure from inland. (I consider the local caves micro when compared the to entire Yucatan.) The caves we dive are just happy accidents from the ancient past that provide us with hours of enjoyment. It is my unscientific opinion that Patricia’s findings suggest the following, “where the fresh water does flow in the direction of the cave, it is a coincidence”. It is my belief that the Yucatan is too porous and large for the relatively small cave passages to have meaningful effect on the macro movement of the water.

Patricia’s presentation was a call for further research. Every year, as more caves are mapped and more research is completed, we learn more about our favorite dive sites. Sometimes new information turns our commonly accepted knowledge on its ear and forces us to consider that our world is ever more complicated and beautiful then we expect.

I recieved the following invitation for a talk here in Akumal this Friday. I was instructed to pass it on. If you are in town, come and join us.

Friday May 23, 2008
Starting at 6:45 p.m. - ending by 8:45 p.m.
CEA CENTER

Recent expedition results from the Cayo Caguanes coastal area of Cuba

Pat Kambesis, Hoffman Institute, Western Kentucky University, Bowling Green, KY, USA;
Like Lace, Cave Research Foundation (both).

Recent expeditions to Cuba’s Cayo Caguanes area are contributing to the knowledge of the coastal karst system there. This is a particularly interesting area for exploration, as the processes that created the explored karst and caves have not yet been fully explained. The Cayo Caguanes karst is of great environmental interest for the extensive and sensitive coastal ecosystems with which it is associated, from reefs to mangrove swamps.

Coastal Cave Development in Puerto Rico

Mike Lace, Cave Research Foundation (CRF).
Pat Kambesis, Hoffman Institute, Western Kentucky University, Bowling Green, KY, USA, and CRF.

A detailed examination of cave resources on Puerto Rico, and nearby Isla de Mona, has revealed abundant and varied examples of coastal speleogenesis on these complex carbonate island platforms. Isla de Mona harbors some of the largest documented caves formed by saltwater/freshwater mixing zone dissolution in the world. On the Puerto Rican mainland, prominent sea cave (littoral) development was noted in all coastal areas but previously undocumented examples of flank margin speleogenesis were also identified. Using detailed cave cartography and a new image analysis method, we have been able to differentiate coastal caves by the mechanisms which formed them in this and other island settings.

What's the Point? Why we map caves

Aaron Addison, University GIS Coordinator, Washington University in St. Louis, MO, USA, & CRF.

Why do we survey caves? It is a lot of time and work under less than ideal conditions to map a cave. In the end, there is a method to the madness and this talk will explore how all the cave mapping activity is working towards a common goal of resource protection.

Formation of Quintana Roo's Beach Ridge Caves

Simon Richards, Cave-Exploration.com

Based on the results of several years of exploration by Jim Coke and others, clues are beginning to emerge about some aspects of how these caves formed. Simon Richards will be describing observations in the caves and how these are interpreted in terms of cave formation.

Recent discoveries about the Yucatan cave hydrology and geochemistry

Patricia Beddows, Research Fellow, McMaster University in Hamilton, ON, Canada

The regional development plans include building at least 5 medium-sized cities along the length of the Caribbean coast. The increasing urbanization requires detailed knowledge of the aquifer and underground river networks for more sustainable management of water resources, waste disposal, and general environmental issues from the jungle to the Mesoamerican Barrier Reef System. This presentation will describe some of the recent scientific findings and discoveries about the cave hydrology and chemistry in part support by the Quintana Roo Speleological Survey (QRSS) with implications to designing environmental monitoring and development.

I made my second cave dive at Pet Cemetery in Sistema Nohoch Na Chich looking for the Blue Abyss and what I discovered is that the map of Nohoch that I have access to, has nothing to do with the lines and cave underwater. As I understand it, the map of Nohoch was created by a large team of people with varying degrees of expertise in cave survey. Therefore, it is notoriously inaccurate. Plus lines change all the time and new discoveries are made. I have ceased to rely on that map and have started to develop my own very nice stick map of the area.

Today’s dive was a big success! It started with an o-ring extruding from an omni swivel when I got in the water and I was doing my predive checks. In less then 100PSI, I had the value shut down. A couple of minutes later, I doffed both tanks, removed the regulator and headed back to the 4Runner to make a repair. Past experience with another leaky omni swivel had informed me that I didn’t have the correct o-rings to repair it. So, I dug in the trusty tackle box and pulled out a replacement 120 degree Scuba Pro swivel. I really like the Scuba Pro swivels for a couple of reasons:

• Only one dynamic o-ring and it is captured.
• It has a fixed angle that places the regulator nicely.
• It is tiny and doesn’t change the weight or hose length dramatically.
• It seems less failure prone because there is no screw on a dynamic turret holding it together.

So, if you have a choice, go for the Scuba Pro swivels. The repair made, I started my dive. The guys where working in the Cenote again dredging it out, so viz was crap for the first couple of minutes, but it cleared up nicely. This time I went left at the first T. When I got the second T I had a decision to make, and based on the compass heading I elected to go left. The line passes through an extensive area of open water dome and then plunges down a sandy hill into the cave. Immediately I was excited. The cave was really beautiful. After a reasonable swim, I came to a nasty looking restriction. My research later revealed it is called, “Tanks on, tanks off ” It is a fantastic window in the rock face. It is smooth all the way around. From my direction you have to pass through it by going up and onto a bedding plane. I looked at it for a second, unclipped my right tank, swung it out in front and passed it with my shoulder dragging a little. SIDEMOUNT ROCKS!

My first impression was it would be a challenge in backmount or impossible if you are a big guy. The only hope would be to go through on a funny angle. However, returning through it in zero viz in backmount sharing air would have been a supreme challenge. To be honest, returning through it in sidemount under stressed conditions would have been a challenge because there is limited room to setup on the other side. So I added a little padding to my gas to ensure a stress free exit.

As I continued the dive taking notes and enjoying the breath taking formations, I realized the line changed type and I hadn’t noticed. The line was a thick white line, the thickness of kermantle, and now it was knotted exploration line. This startled me for a moment and I had to make a decision to back track and note the line change and confirm I was on the right line or continue on and trust everything was ok. I decided to back track and put those devils to bed. Over an arrow, up through a minor restriction and there was the junction. It was about 2 minutes back. I took a mental note and continued the dive.

It is this kind of realization that starts to build mental stress. The feeling of not knowing or feeling lost is insidious. Couple the change in line, the lurking idea you might be on the wrong line and another crisis of your description and you have a recipe for a full on fear fest should something nasty go down. Progressive penetration and awareness are keys to survival. There is no reason or goal that should drive you to skimp on something as small as a two minute back track to confirm your location.

I swam to the end of the line. It took me about 40 minutes and less then 1000PSI with my back tracking and extensive note taking. The line terminated just a couple of feet short of another line, which I believe to be the Diaz Line. The return swim took about 30 minutes and about 500PSI. There was a section on the return swim with decent flow that slowed me down. But it is only a hundred or so feet long. I wonder where all that water is coming from and where it is going. Because it doesn’t pass through “Tanks on, Tanks off”.

When I got home I drew my stick map from two days of diving. It is a supremely satisfying feeling to look at the new map and know you have been there and you have a foundation for future dives. I have to thank Patrick for that. He is the one that got me to be more disciplined in my note taking and drawing. And he gave me a system.

I was supposed to go diving yesterday afternoon. However, I had to abondon that idea becuase I was having a bad day and I didn't want to take that in the water. Instead I watched 8 hours of the TV series 24. I serviced some of my spools, fixed clips to 2 of my new LED SL4 lights and put my new yellow SL4 lights on my purple side mount helmet. I am happy to report that I look stunning with the helmet on. Skipping diving provided me a mindless break. And I wanted to get some more work done.

Today, I made up for the postponement. I decided to go back to Cenote Minotauro for a nice cave dive upstream. However, this time I went up stream on the downstream line. I am sure there is a name for this line, but I don't know it. If you do, let me know?

It is a very beautiful dive. It is tight. I was up there once in backmount with a buddy bottle and in retrospect that was a bad idea. After that dive, I pledged to not go back until I was in side mount. This time I went side mount and it was a pleasure. I can't imagine diving there with anymore then 1 buddy. There are tons of lines and jumps everywhere you look and lots of fragile stuff that can be broken.

This dive I decided to practice taking notes and doing a rough stick map of the cave. Wetnotes and digital compass in hand, I set to work. It ends up, I am a terrible judge of scale and it is easy to get lazy. Looking at the map, I should have really started much smaller and skipped the whole compass bit. I ended up going off the page and having to come back on the other side. I remember doing this as a little kid when I drew mazes. I think a first pass at a simpler stick map would have been sufficient. Or maybe just an accurate log of the line directional tendency, jumps and T's.

The wetnotes and digital compass suck together. The compass is part of my Sunnto D6. To take a heading, I have to hold the button down and wait for it to switch modes. Then after short period it switches back to computer mode. There is no quick way to record the information I want. Every time I have to stop and wait for the equipment. I really makes taking detailed notes no fun. So between the wetnotes and the Sunnto, my work was much harder then it needed to be. I think I am going to give it another try with a standard compass and a slate.

All that aside, I think the map I created will be useful in deciding on future plans and places to check out. I made it about 30 minutes back when my primary light died. This is the second time in 2 dives it died in less then an hour. Note to self, "Once is fine, twice is something worth paying attention to. Do use that battery again without getting it fixed." This is a huge bummer. One light is flooded with a broken cord. Two batteries were flooded in the process and now the third battery is on the fritz. I am glad I got a backup primary light but jezz, I don't want to have to buy two backup primary lights. I hope that made someone laugh.

I noticed my primary flickering a little, then I thought, "Hmmmm... that seems a little dim." I turned on my helmet mounted LED SL4 and BAM! It was brighter then my 10watt HID. Now, I believe the HID is dying.  I turned it off and turned the dive.

I have to say that I am VERY happy with the LED lights. I have two of them mounted to my side mount helmet and they are stellar. Beam is brighter and whiter then my Photon Torpedoes. Reportedly they should burn for a much longer time then the traditional bulbs. Of course, this remains to be seen. In a cave as small as this, the 1 LED light was plenty. It doesn't have the reach, but in good vis it is good for 15-20 feet. If I wanted more light, I turned on the other light for a moment, then killed it.

On the return trip I checked out some of the other arms of the T's. There is definitely more cave to explore up there. I also made the jump that leads to the main up stream line. This was a very very cool little extension to my dive. You have to descend head first through a Z shaped passage. I know people do it in backmount, but it just seemed too small to do in good conscience. It was very very cool and I feel very lucky to dive this stuff every other day. I followed it to the main upstream line. About 2/3 way there, I realize I had been on this section of line before. I had aborted my attempt from the other direction because I was on my rebreather and it was getting too tight and I didn't want to damage the cave. After I finished this section, I headed to another jump I had started to check once before, this time I was successful. I found the end of that line and a fork. At this point, I had been swimming for 102 minutes and it was time to go. I promised Allie I would call at 6PM and it was now 5:50pm. So I cleaned up my stuff and headed home. I am very satisfied that I made a beautiful dive and my mind was in the right place.

Max Depth: 32ffw
Run Time: 113 minutes