The depths some people dive will take your breath away. From the earliest times, people have taken the plunge, but today freediving (diving without breathing equipment) is an extreme sport that pushes the human body to its absolute limit. Participants plumb the depths on just one deep breath.
Holding their breath for minutes at a time, freedivers plunge to depths of more than 100 m (328 ft). Divers train themselves for the challenge mentally and physically, but in some ways the human body is hardwired to undertake this amazing aquatic activity. When submerged in cold water, the heart rate slows to conserve oxygen. The blood moves away from the arms and legs to protect the vital organs. At a depth of 100 m (328 ft) water pressure compresses human lungs to the size of fists.
Competitive freediving has different disciplines depending on what equipment the diver uses. “No limits” freediving involves using a weight and cable to descend very quickly. “Constant weight” freedivers descend and ascend under their own power. They can use a 
weight to help them descend, but must return to the surface with the same weight.
Freediving for Food
The Bajau people of Borneo are real water babies. Their houses stand on stilts in the sea, and they freedive in search of fish to eat. The best Bajau freedivers can stay submerged on a single breath for up to five minutes, diving to the bottom of the reef 20 m (66 ft) below.
