I had a true bucket list experience recently when I learned that my research would be featured in the January 29th, 2015 post of National Geographic Online, and that a photo of me would be included in the article. The article is by Dan Vergano, and entitled “At Newly Discovered Water Temple, Maya Offered Sacrifices to End Drought.” It describes the underwater archaeology work that Lisa Lucero and I have done at an ancient Maya site at the Cara Blanca Pools, Belize. Specifically, it talks about last summer (2014), when Lisa and her students excavated Structure 1 at Pool 1 (the “Water Temple”), while the divers and I continued our underwater explorations. Please check out the article here.
About half way through the article, there is a photo that is entitled “Scientists collect samples for carbon dating from trees at the bottom of a pool at Cara Blanca (copyright Tony Rath)” Here is a copy:
I am the diver on the left holding the saw, cutting into a submerged tree in order to remove a wedge of wood for Carbon 14 dating. I remember this dive well, but my memory has very little to do with tree samples. What the photo does not show is how tiring it is to saw ancient wood at 70 feet below the surface while trying to float in the same spot (what is called “neutral buoyancy” in diving). It must be similar to working in space, where any push against the tree trunk with the saw would have an equal and opposite reaction in the form of me floating away from the trunk. Look at my left hand in the photo – as you can see, I was forced to grip the trunk with my left hand and saw with the right, while still keeping my breathing under control and my buoyancy neutral. The other diver and I took turns, one sawing while the other bagged the wood samples, for about 40 minutes. When I would feel my breathing get too frenzied, I would have to force myself to keep it under control and slow my lungs, while at the same time sawing, holding onto the trunk, keeping neutral buoyancy, and attempting to not cut myself or my air hoses with the extremely sharp saw. I also had to make sure not to drop the saw or the plastic baggies containing the samples.
While it was an operation that seemed to require three brains, I was being successful! Methodically, myself and the other diver collected our samples, moved between the trees, and made no mistakes. During the last few minutes of the dive, I noticed my breathing was really starting to get heavy. I was in control, I had plenty of air in my tank, but I was getting very exhausted. As we bagged the last sample, I made the familiar sign to go up (a raised thumb, hitchhiker style). My buddy signed an “okay,” and would join me at the surface in a few minutes.
I began my ascent, and did the required three minute safety stop at 15 feet. Everything went perfectly, but I was exhausted when I reached the surface and I felt very queasy and generally out of sorts. I pulled the regulator out of mouth, floated on my back and looked at the jungle sky, breathing very heavily and forcing myself to focus on my situation at hand. A 70 foot dive is not very deep, and I had done nothing wrong during the dive or as I surfaced. While half of my brain worried about serious problems like the bends or an air embolism, and knew that the type of first aid required for those life-threatening situations was impossible to come by in the middle of the Belizean jungle, the rational half of my brain knew that these situations were highly unlikely. As I floated around, I started to feel a bit better and I climbed out of the water. As the other divers surfaced (there were five of us that day), the photographer who took my photo (Tony Rath) also complained of feeling much worse than he thought he should. His symptoms, and the possibilities for them, were the same as mine. We figured that there were two possible reasons for this:
1. In our zest to collect Carbon 14 samples and take great photos, we each independently over-exerted ourselves and our systems could not take it.
2. The oxygen in our tanks was contaminated.
Over-exertion was a much more probable explanation than bad air. A tank can be filled with impure air if the air pump is set up incorrectly, where the pump sucks exhaust fumes into the tank. The divers on our crew were consummate professionals, so the chance that they set it up wrong was miniscule. There was one more dive scheduled for the day, and as we ate lunch (and Tony and I continued to feel better, but not fantastic), we discussed the afternoon dive. Chip Petersen (owner of Belize Diving Services on Caye Caulker in Belize) was our acting dive master, as he was easily the most experienced diver on the team. It was up to Chip whether we continue with a second dive or not.
It would be a much, much better choice for the project if we completed a second round of dives. Getting tanks and dive equipment out to a remote Maya site is not easy; it takes months of planning and lots of money. It is also not easy to schedule all of us to meet in Belize during the same few days a year, so time is very precious. To complicate matters further, the weather had been very good, but the rainy season was threatening, and a big storm could come along any day that would wash out the roads. This would make the pools unreachable by truck, and any unfinished diving would have to be cancelled and re-scheduled for the dry season of the following year. Additional diving the following year would also require new funding and a new permit.
I thought we were going to do another dive. As I finished my lunch, I thought I felt good enough to go; I was not at 100%, but I was more than okay to do another shallow dive safely. As I readied my equipment for a second dive, Chip decided to call the dive off. His reasoning was that even a remote possibility of air contamination in the tanks could have disastrous results in a remote dive location like the Cara Blanca Pools. Nobody complained – the dive master’s word is final. We disassembled our gear, got back in the trucks, and headed back to camp. By dinner time, both Tony and I were fine.
Chip made a great call. People like him are indispensable on an archaeological project; those who will make a tough (and possibly unpopular) judgment call for the greater safety of the crew. Under his leadership, everyone got home safe. We ended up with plenty of Carbon 14 samples and stacks of amazing photos. The weather held, and nothing had to be rescheduled. We even made it into National Geographic.