In 1976, French diver Jacques Mayol became the first human to descend to (328 feet) 100 meters [source: Independent]. Mayol, who studied Indian yoga and the breathing techniques of kung fu-practicing Shaolin monks, adapted those mind-body control methods to slow his pulse from 60 to 27 beats per minute underwater, enabling him to dive deeper and longer. In doing so, he revolutionized freediving and paved the way for Herbert Nitsch's generation of divers to push the limits even further.
It's fairly easy to get into freediving. It doesn't require a lot of expensive equipment -- a wet suit for warmth, a mask and a set of special flippers designed for underwater efficiency can be had for less than $1,000. And according to freediving expert and author Terry Maas, with competent instruction and a little practice, novices quickly can learn to stay under for 45 seconds, long enough to descend as far as 30 feet (9.1 meters) and experience the ocean from a startlingly new angle [source: Maas].
But going without oxygen for longer periods and diving to serious depths isn't for dabblers. Elite divers must endure rigorous training to develop their lung capacity and control their pulse rates. They also utilize special safety equipment, such as balloon systems to help them return to the surface more quickly.
Even then, tragedies sometimes occur. In 2002, elite French diver Audrey Mestre was attempting to set a no-limits depth record off the coast of the Dominican Republic, when equipment malfunctions apparently kept her underwater too long. She lost consciousness during her ascent and perished [source: IAFD]. Another French champion freediver, Loic Leferme, died off the south of France in 2007 when his ascent rope became snagged [source: Dive Magazine].
Learn more about water sports and other adventurous activities by clicking through the links on the next page.