11 Things You Never Knew About Freediving

Jimmy Hex, author of Deep: Freediving, Renegade Science and What the Ocean Tells Us About Ourselves, tells us 11 fascinating things about the extreme sport of the moment. Read, then tell us whether you’d dare try it yourself…

1. As infants, we can comfortably hold our breath underwater for more than 40 seconds, more than many adults. We’ll instinctively start breast stroking and open our eyes. We only lose this ability when we are taught how to walk.

2. Dolphins, whales, and other marine mammals have special reflexes that allow them to dive to incredible depths without being crushed by the pressure. We also share these reflexes. Some freedivers have honed these reflexes to dive more than 700 feet beneath the surface!

3. The second you put your face in water, something amazing happens: your heart rate lowers up to 25 percent; blood starts rushing from your extremities into the core; brainwaves soften. These reflexes — which occur only in water — allow you dive deep for longer than you would be able to otherwise. And the deeper you dive, the more reflexes kick in, eventually spurring a Hulk-like transformation within us. The equivalent pressures on land would kill or injure us. But not in the ocean.

4. Past around 10 meters, buoyancy reverses; instead of being floated to the surface, water starts sucking us down. It feels like gravity is reversing. Freediving call this the “doorway to the deep,” a magical place where everything changes.

5. Heart rates of freedivers on deep dives have been recorded as low as 7 beats per minute — about three times lower than a coma patient! Physiologists have argued that a heart rate this low can’t support consciousness, and yet, deep in the ocean, it does.

6. Freediving is liberating: unlike scuba divers, freedivers can dive and ascend in the water as fast or as slowly as they’d like. Freedivers can’t get decompression sickness — which is caused by nitrogen bubbles entering the bloodstream after breathing compressed air. The human body naturally knows how to purge dangerous levels of gas from the body. All you do is breath up and let your body do the rest.

7. Ancient cultures around the world have been freediving for food, pearls, coral, and sponges for tens of thousands of years. We only stopped freediving in the last few centuries, as fishing technologies advanced. Sailors in the seventeenth century reported seeing freedivers plunge to depths of 30 meters and stay at that depth for up to 15 minutes at a time! Scientists in the 20th century discounted these reports as fabricated, however, today competitive divers are holding their breath more than 12 minutes. If they continue progressing at their current rate, they’ll bust the 15-minute mark in the next few years.

8. Freediving is the most intimate way to connect with the ocean: freediving is silent, which means freedivers don’t scare off fish and marine animals when they are underwater. Instead, the animals become docile, even playful. They often welcome freedivers into their schools. No other activity can get you as close to ocean wildlife than freediving.

9. Your blood contains a 98% similar chemical composition and almost the exact same pH as ocean water. We’re all born of the ocean, and each of us has our own little ocean within us.

10. Freedivers aren’t special. Right now, with a little training, you can hold your breath for 2, maybe 3, maybe 4 minutes. Every human shares these amphibious reflexes. To feel them, you just take a breath and jump in the water.

11. Freedivers never, ever dive alone. If you ever want to try freediving, take a course. Always know your limits. Respect the ocean. And never, ever dive alone. (Freediving is more fun with a friend anyway!)