Lettuce Cave is a river cave with many high ceilings. Currently, no end has been found, despite expeditions of up to four days. Bro called Jorge, the owner of the property with the entrance to Lettuce, the night before to ask permission. Jorge said of course we could come to go in Lettuce.
The main danger, he explained, was flooding. A low ceiling inside had blocked off return passage for prior cavers, forcing them to swim a few feet underwater, in a current, to leave the cave. This scenario we wanted to avoid, and Jorge assured us we would be fine as long as we were out before rain. He took us to the lower river entrance and wished us well.
The river entrance was mostly shoulder-width, head-high and chest-deep for 500 feet. This brought us to a small waterfall coming from a squeeze just a few inches wider than my helmet.
We upclimbed the waterfall and entered a huge room with a manmade dam and sandy pool. The water was very warm.
We walked up the pool for a few minutes until coming to a narrow constriction in the stream, passable by upclimbing and stemming. This dropped us down into another pool, where we swam beneath the low ceiling which can create a sump even in small flooding. I was a few hundred feet ahead of Suhei.
I came to a fork. The stream came from a small passage on the left, and on the right there was a large room of white formations. It was spectacular. I was feeling rather winded, and a headache that was slight back at the dam was now becoming severe.
I sat down. My resting pulse was close to 200. I was starting to feel dizzy. I tried to breathe slower, but felt like I was short of breath. I was about to lay down when Suhei came up and said she felt sick. She complained of a headache, dizziness,
and shortness of breath. I was ready to faint. The formations seemed to be spinning around me. Firmly and immediately I said we are leaving.
We took off. My pulse was racing, as was Suhei’s. I felt dizzy and was moving slowly. The entrance seemed so far away, even though it was less than an hour. I couldn’t avoid the thought that I could pass out at any moment, thinking of the effort it would take Jorge to come in and haul us out, unconscious or worse, if we missed our check-out time.
This was my first time in bad air in a cave.
We worked our way back. I fought the urge to faint, and started feeling better after a lengthy ten minutes of progress. My pulse came down, but the headache was still pretty bad. We resisted sitting down to rest, knowing that getting to better air was the only solution.
By the time we got back to the dam, we both felt a lot better. My pulse was around 80. We rested, breathed deeply, and left the cave, again through the tight, long river entrance.
When we got out, Jorge told us that there are indeed pockets of bad air in the cave. He explained that the frequent flooding during the wet season flushes out the bad air, which is contrary to what I had learned prior. Three separate speleologists in Arizona had told me that air quality decreases, not increases, during rain, because rain washes dead, rotting, organic matter into caves, which produces CO2 and other gases. I would assume the same is true for Puerto Rico, but Jorge disagreed. Regardless, both of us felt very sick in Lettuce.
We were only in the cave for two hours, a disappointment for such a long and amazing cave, but were glad to get out without passing out. It was a definite learning experience for us, to go slow, listen to your body, and always be ready to turn back when necessary.