Today, I was caving alone in the Webster System, KY. That is, I was by myself, but others were ahead and behind. Anyway....
I was caving in the dark, being very familiar with the twists and turns, rocks and mud banks, of this particular stretch of lake trunk passage. After about 15 minutes of this, my eyes were quite dark adapted. Suddenly, I became aware of a light-sensation on my wetsuit gloves and my arms. Small specks of light. They appeared to be attached to my suit, but sometimes appears to "flow" away and behind me as I swam and waded.
At first, I thought perhaps my gloves had phosphorescent paint on them. No. Then I thought maybe it was my eyes playing tricks, like when you rub your eyes in a dark room. Later on, a few minutes, I saw them again. It appeared to manifest itself if I agitated the water around me. Cosmic ray strikes? Unlikely underground, I thought.
After a few hundred more feet, I stopped, and looked down. The water was about chest deep. Still in total darkness, I saw a tiny speck of light directly in front of me. Not moving, and I was able to focus in on the speck. I turned my light on and was able to identify a very small white object, much smaller than the head of a pin, floating in the water. It was the source of the light I had been seeing.
I've never heard of anything such as this before, and had never witnessed it prior to this. My eyes had been very well dark adapted before I noticed it. Could it be chemiluminescence, or something biological?
Any ideas?