As much as I like the JREF and Randi's mission to discredit all the scam artists and charlatans in the world, I find this issue, and this board's hangups about it, to be very, very strange.
In the first place, I have a master's degree in Physical Geography. I worked as a scientist for years in one of the most cavernous areas of North America, the corner of Tennessee, Alabama, and Georgia (also known as TAG.) I still go there for caving at least twice a month.
Argumentatively, Randi certainly has a leg to stand on, because he specifically discounted caves from his list of "underground rivers." I just think it was a damned weaselly thing for him to do. Essentially, he said that "no underground rivers exist, except in places where they do, in fact, exist (defined as a large underground conduit that carries water), and those don't count," defining any "large underground conduit that carries water" as a cave, and therefore excluding them from the argument, so NYAH NYAH NYAH.
Yes, underground rivers exist. Wekiwa Springs, in Orange County, Florida, has a flow of 62.6 cubic feet per second. That's over 40 million gallons per day. That's quite enough to qualify for the term "river." Hell, there are surface streams in the West that people call "rivers" that don't have that much flow. I've swam through underground rivers. I have PHOTOS of underground rivers. I've done years' worth of work in underground rivers. That they exist is absolutely undeniable.
Now, I know that this won't qualify for the MDC, but this seems to be a case of the JREF forums folks defending Randi's every word and utterance. What should happen here is that Randi should say, "OK, I screwed up. There are, in fact, underground rivers. I meant that dowsers' conception of groundwater hydrology is deeply flawed, and not based on any scientific understanding, but rather some pseudoscientific mumbo jumbo. What I mean to test is a paranormal claim to be able to 'sense water' underground, or to be able to demonstrate the presence and location of 'underground rivers' by use of a paranormal method."
And no, Peter, you're never going to see your million bux. Nor should you, because you're trying to exploit a nonexistent loophole in the MDC. The idea is not to catch Randi in an ill-advised linguistic slip, but to prove that the paranormal exists.
That doesn't mean, however, that Randi was not factually wrong in this instance.