How many People Do "Free Diving"?

I was surfing YouTube, and came across the tragedy of one Audrey Mestre (died whilst attempting the world’s deepest “free dive”).
For your info, “free” diving involves diving while holding your breath-you don’t use an aqualung or other source of air to breath.
You simply take a deep breath-and hold onto a weight (running along a cable anchored to the bottom). You try to go as deep as you can-when you reach your limit, you open a valve, which inflates a balloon-which pulls you back to the surface.
This seems a tad dangerous…and odd as well-does anybody really care who was foolish enough to reach 600 feet?
In any case, are there a substantial number of people who like doing this?
To me, its the kind of competition that ought to merit the “Darwin Award”.:smiley:

There was a really bad movie about free diving in the late 80’s/early 90’s. It seemed cool to me at the time, but free diving seems stupid now.