A summer day in Central Texas. It's 10 a.m. and the temperature has already reached 32°C. Walking through the gate at the Barton Springs pool with your snorkel and mask in hand, you hear the water splash. Another Austinite finds respite from the heat in the cool, clear waters of the pool. You walk to the edge of the pool, then one quick jump and you're in. For a moment you are tempted to float lazily on the water, but your snorkel reminds you of your mission. You pull the strap of the mask over your head, grab the mouthpiece of your snorkel, and sink into the depths. You kick your way down to where the icy waters of Barton Springs percolate up from the Edwards Aquifer. You are alone beneath the surface of the water. Or are you?
