"Cave diving: It's not for everyone."

That's how you're greeted on the homepage of CaveDiving.com, and it should prepare you for what's to come. Expect little encouragement if you voice interest in this sport.

It's true that cave diving is dangerous, treacherous, serious. Wes Skiles, an avid cave diver with quite a few near-death experiences under his belt, tells the straight story both on his site (CaveDiving.com is his brainchild) and in person. In explaining the sport to Fast Company, Skiles said, "If you take average, experienced divers and put them in an underwater cave environment, you expose them to all sorts of risks that they don't understand and that they're not prepared to deal with. They would certainly die. And it would be a hard, terrifying death."

So why do people do it?

Well, as expected there's the thrill. In a world where SUV commercials assure you that the CD won't skip while you go offroading, it's rare to find this sort of unbridled danger. "There's no injury rate," FC says with an air of doom, "only a mortality rate."

And then there's the pioneer spirit. No one has been there before. You are the first one to see the tunnels, the bones (prehistoric findings like mastodon bones, for instance), the underwater chambers that look like nature's naves.

You learn self-reliance. Cave diving is man against the elements — you have to take doubles of everything (two tanks, two lights, two regulators) and you have to maintain, above all, your powers of judgment. While open-water divers are constantly warned to dive with a friend, cave divers need to be confident in their own abilities; relying on another diver to know when to come up ("call the dive") could mean the difference between life and death.

You practice self-mastery. In the most threatening situations of cave diving, you need to be calm enough to master even the most basic bodily reactions. You need to talk yourself out of letting panic-causing endorphins and adrenaline take over.

And you come out of it with increased authority. If you can cave dive, you can damn well tell some fool at work to buy and not sell. Your confidence spills over into other areas of your life. You have felt the "weight of the unknown," and you have survived.

Still think you can do it? Find an instructor: The Global Underwater Explorers, National Association of Cave Divers, and National Speleological Society Web sites can help.

Then, find out where to go in: