In my quest to acquire still more bad-ass but useless skills, I took a course in high altitude diving. Lake Atitlan sits at 5000 feet, which means the air pressure at the surface is 15% lower than sea level. Because dive tables and depth gauges are all calibrated to one atmosphere, this necessitates slightly different protocols. Nothing too fancy, but I got to dust off some of my rusty knowledge of partial pressures and Boyle’s law.

Because the boat we dove off was quite small, we suited up on shore. Nothing felt quite so silly as walking past women in traje while wearing a wetsuit and carrying a tank of air.

There’s actually very little to see in the lake, so the altitude is the interesting part. We saw a drowned but standing tree, some volcanic formations, some warm mud due to underlying activity, and several tire-fish and cans of Gallo. More exciting than my training dives in Lake Mascoma, but only by a little. But now I have an extra PADI certification, and another useless skill under my belt.