Diving at station C6C in the northern Gulf of Mexico, south of Terrebonne Bay. This station is in the heart of the “dead zone”- a region of seasonally hypoxic bottom water that can span tens of thousands of square kilometers. The dive demonstrates the beautiful green water of the upper water column, shimmering water created by the halo cline, and the murky, low visibility hypoxic zone of bottom water. Shot by yours truly with a GoPro Hero4 as part of the CBS News feature on the region. First of three parts.