This if mainly an ecology video about a study of the Kharst System of Florida. But they do use a cave diving team to do the exploration.
If you have considered taking up cave diving, watch something like this. You get to see some of the real challenges of diving through a cramped and silted up cave system. Areas that they had explored in the past had collapsed. Gear got snagged and equipment failed. Some of it was obviously played up for drama because they have a camera crew with them. They are also often following previously laid line, though they do occasionally lay new line. The whole process of exploring 10 miles of underwater cave system is tracked from above with a receiver as the support team follows along. The cave divers are Tom Morris and Jill Heinerth.
They constantly discuss the effects of pollution and other human activities on ground water. They discuss different ecological protection
measures that are being adopted in Florida from farming, waste management, and home owners perspectives. There is some good information here. Again, I think they overstate things sometimes because they are constantly discussing the pollution of ground water but at the final spring where the divers come out of the system, the team leader just gets down in the water and takes a straight drink. I’m not saying that the problem isn’t real, but overstating things will come back to bite people in the butt later if people think they were lied to.
I will warn you though, the number of bad puns in this film is incredible. I origionally ran across the dvd in the resources section of an article on cenotes in either Discover or Scientific American. Reading with an open mind can take you to all kinds of new sources.