Monday 22nd March 2004
I’m back in the black again. I’m back.
Ha ha. Sinus and ears doth not fail me now.
Clearly, health has return and the diving continues with a vengeance. Cenote Raphael was the point of contact today. Team Three (Annie Rudy, Amanda Massie, Woody Dunkum and their teacher Shane Newcombe) from the Fuqua School assisted in our diving operations today. Raphael is the neighboring system to Cenote de Muchachos. It lies some 1,500 feet/450 meters away. Renee, Karl and I made our way down to the deeper section of the cave. My primary light shut down and would not relight. It would fire, but not stay on.
So, I went back to my training once again. Secure the line, turn on the backup light, signal for buddies, turn the dive and return to the cenote. We had been diving with four cylinders; we staged two of them at the entrance “T”. So, we put back on the additional two stages and returned to the surface. The entrance to this cave has very little flow and has a large calcite mound right at the entrance with a small restriction. So, visibility goes to zero when entering.
A “T” is an intersection in the line. We place non-directional markers on the exit side of the “T”. Systems that are being actively explored usually have “T’s” at every intersection. Once a system matures some, the “T’s” are cut back into jumps (A jump is a gap between one line and another.). This is what we were doing earlier in the week in Cenote de Muchachos.
Once we returned to the surface, Karl decided his ears were not going to cooperate today. He was able to make it down, but the return trip was painful. He said, “I made it down fine, but on my way up, my ears said oh you want that air to come back out do ya. Fat chance.” So, he decided to sit out the redo.
Karl was nice enough to loan me his Dive Rite 10 W HID primary light, so I would be able to continue diving. Renee and I reentered the system keeping our stages on this time. We checked the deeper passage for leads. None were found. This side of the system is all below the halocline.
A halocline is a boundary area between fresh and saltwater. The increased density of saltwater causes fresh water to float on top of it. It creates a boundary that literally looks like oil and vinegar as you swim through it. When you drop below the layer you can see clearly and when you pop above the layer you can see clearly. When you swim within a few feet of the layer you cannot see well at all. It looks very murky. In some of the systems, the halocline is so defined that you can literally see the fresh water flowing on top of the saltwater.
Another interesting aspect to diving through the halocline is its affect of your buoyancy. You are adding air to your BCD as you go deeper while diving because of the increased pressure. When you reach the halocline you have to actually let air out of your BCD because the saltwater layer is causing you to be more buoyant. You can actually end up rafting on the saltwater layer. It is a strange feeling the first time you have difficulty descending because you are too buoyant, yet you are not rising in the water column. It feels almost like floating on the surface. You have to decrease your buoyancy a surprisingly large amount to regain normal buoyancy control.
Generally, the halocline becomes deeper the further from the ocean you travel inland. The halocline is a critical indicator of the health on a system. If excessive fresh water is drawn from a system saltwater can be drawn up to a higher level. If the rise in saltwater is high enough to reach the wellheads, the wells will no longer be usable. Saltwater incursion is a growing problem throughout the world. The halocline is this interface.
After we returned to the entrance line, we decided to check the shallow side of the system for leads. We checked several long leads that did not pan out. The cave looks very similar to the cave at Cenote de Muchachos. More leads remain to investigate.
Team One (Brian Mackintosh, John “Boz” Boswell and Josh Owen) of the FuquaSchool spent their day with Terrence at Aktun Chen. They were using what they learned last night to survey the cave that the facility needs a map of. They laid 1500 feet/450 meters of line. Preliminary survey was completed and side passages noted. They plotted their data once they returned to Villas DeRosa. They saw frogs, crayfish, bats, scorpions, isopods, and many more cave creatures.
They also got a first hand lesson in cave formation and hydrology. They saw cave decorations, cave pearls, cofferdams, and a wealth of other speleothems. The students named one formation Helm’s Deep after the Lord of the Rings. They said it looked like Helm’s Deep from the movie. They all had a great time.
Team Two (Meg Barkley, Meagan Jones, Jeremy Wyatt and their teacher Dora Bounds) from the FuquaSchool joined Amy to help with her scientific sampling at almost all the cenotes of the systems. They visited and took samples from Cenote Carrie’s Loft, Cenote Camilo, No Name Cave, Cenote de Muchachos, Cenote Mud, and Cenote Raphael. The students were responsible for all of the scientific data that had to be collected. They enjoyed getting to go through the jungle to do science truly in the field.
There is nothing like visiting the living laboratory to re-enforce the lessons learned in the classroom. These students will remember these moments for the rest of their lives. It is the mission of the Cambrian Foundation to raise awareness about the aquatic realm through exploration, education, preservation and research. This expedition is the perfect example of all four missions coming together in one project. Everyone involved in this project is very proud of the enthusiasm and intelligence of this group from the FuquaSchool. It is through the hands of the next generation that we pass what we have learned ourselves. Together we all can move toward a better understanding of the aquatic resources we have, both those discovered and yet to be discovered.
For detailed daily updates checkout www.cambrianfoundation.org.