On this last dive trip to check out bridges up north before the snow flies, the smallest and most unassuming structure of the bunch ended up providing the most notable lesson of the week - don't let your gaurd down, assume things or get bored or you'll make a mistake. This unimpressive structure had only a pair of footings in shallow water in a nondescript stream with no discernible flow. It was just after lunch, so feeling lethargic from the morning's dives and food, I suggested it'd be a good training dive for our newer dive inspector. Probes along the bottom of the sheet pile with a level rod revealed no hint of problems , and about 9 or 10 feet of water at the most. Since guidelines for the project dictated the PE-Diver has to dive at least 50% of inwater elements for each bridge and this one had two small footers, the new guy ended up running the console topside and I ended up in the water anyway. I groped along in the murk not expecting much of interest, thinking that I was already hungry for my Subway bag of chips I'd saved. Lo and behold, on the deeper of the two footings, the bottom of the sheet piling around about half of the circumference was exposed above the bed about 6 inches or so. Probes underneath revealed a significant void that penetrated back into the original, deteriorted column. The engineer standing on the footing above me reported noticeable vibrations with passing traffic. We ended up with a total of three dives on the footing, with two different PE's groping and probing around down there. Just goes to show you - gottta stay sharp, even on the eazy-cheezy ones.
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