‘Flying underwater’ with a freediving legend

Freediver Guillaume Néry swims with sperm whales off the coast of Mauritius, an island nation in the Indian Ocean.

Guillaume Néry takes a moment to compose himself.

He adjusts his mask, swallows a big breath of air and then dives into the sea.

And he won’t come back up for several minutes.

Néry is a former world champion in the sport of freediving, where competitors eschew scuba gear and rely only on holding their breath. In 2002, at the age of 20, the Frenchman became the youngest world-record holder when he dove 87 meters (285 feet) on a single breath of air.

“When I started when I was young, it was a way to discover my own limits,” Néry said. “I was driven by performance, by this challenge. … But step by step, I discovered that freediving can also be a way to discover magical underwater places.”

Néry swims with sharks in French Polynesia. It has become his favorite spot to dive, and he spends several months a year there.

Néry swims in an underwater cave in Mexico’s Yucatan state.

Néry is the star of “One Breath Around the World,” a short film that explores an underwater world that most of us have never seen.

It splices together footage from dives that Néry has made across the globe, on several different continents. It was shot almost entirely underwater by videographer Julie Gautier, who was freediving alongside Néry.

Franck Seguin, who took the photos you see here, only used an oxygen tank on the deepest of dives.

“The ocean is vast. In it, you feel very, very small, even powerless,” Seguin said. “You can confront all your fears but experience great joys, too.”

The images are stunning, almost dreamlike, with streaks of daylight piercing the deep blue water. The colors change as Néry dives deeper, aided only by a weight belt around his wetsuit.

Néry navigates an underwater cavern in Mexico’s Yucatan state. The red streaks in the background are tree roots that draw their water from below.

Néry swims with a whale and her young near the island of Rurutu in French Polynesia.

In the film, he gracefully navigates underwater caves and leaps off rocks and coral as though he were a natural part of the ecosystem.

“I have this feeling that I am flying underwater,” he said in an interview with CNN.

Some of the most memorable moments are when he interacts with marine life, including massive sperm whales off the island nation of Mauritius.

“You have to move very gently, very softly,” Néry said. “You have to be graceful in the water. And then the connection with the animals can be incredible. … With the sperm whales, they are mammals. And when they see you, a human not breathing underwater, there is a very strong connection.”

Néry exercises great caution around animals underwater. “They are wild,” he said. “That doesn't mean they are bad. It doesn't mean that they will attack you or hurt you. But it means that you need to be aware and you need to believe in your intuition. … You need to be humble.”

Néry dives near the Yonaguni Monument, a mysterious underwater rock formation in Japan’s Ryukyu Islands. Some claim that the ruins are evidence of a long-lost city, while others are convinced it is a geological phenomenon.

Néry has held his breath underwater for nearly eight minutes before, but that was only while staying absolutely still. When he’s out exploring, expending energy, each dive is about three to four minutes long.

“It really depends on how deep I go, how fast I move,” he said. “But you don't really measure the time when you do that.”

Freediving is a dangerous — and sometimes deadly — sport that requires serious training and discipline.

Now imagine doing it while holding a camera.

“It’s no small feat,” Seguin explained. “There are waves, the current, the depth, being far from all immediate help if you drown or feel dizzy. There’s the lack of oxygen if you’re freediving, or getting tired if you have been swimming for 45 minutes behind a whale while trying to catch up with it and capture an image with Guillaume in the frame.”

Néry stands on a tree during a dive in Mexico. Photographer Franck Seguin usually freedives himself when he’s with Néry, and because of that he carries very little equipment. Seguin says he does make minor adjustments to the photos in post-production, removing the occasional air bubble or piece of algae.

“The sperm whales, we stayed one week with them,” Néry said. “At the beginning, we were just trying to understand the behavior. We were working with people that know them. And day after day, we got more confident.”

In September 2015, Néry got a scary reminder of just how treacherous freediving can be. He injured his lungs while trying to break the world record for a fifth time.

He was attempting to dive to 129 meters (423 feet), but someone from the competition made a mistake and set the ropes at 139 meters (456 feet).

Néry made it all the way down, but the record didn’t count because he lost consciousness just a few feet away from the surface.

“It happens,” said Néry, who had blood in his lungs and took a few days to recover.

“But because of that, I decided to make a break with competition. And during this period I focused on this ‘One Breath Around the World’ project.”

Néry swims with a Sama-Bajau fisherman in the southern Philippines. Some of the Sama-Bajau will freedive to catch fish, using the same tools they used 50 years ago, Seguin said.

Néry uses a flashlight while diving in Mexico.

Néry says freediving has become more than a sport to him. It’s a way of life, and a reminder to slow down and stay in the moment.

“People are doing so many things today. They are stressed, they are working too much and always complaining that they don't have time,” he said. “When you freedive for one hour or two hours, you just completely let go.”

Freedivers have to calm their mind and relax their muscles to conserve as much energy as possible. And that lesson translates outside of the water, Néry said.

“From the moment you hold your breath, you just forget about the time. It's like a moment out of time. And when you finish, you feel so relaxed and so peaceful. To me, it became like a philosophy, a way to think better.”

There’s no “winging it” on an underwater shoot, photographer Franck Seguin said, because you can’t communicate effectively once you’re down there. “We talk before diving about what we wish to achieve, the movements we’d like to do, the depth to which we want to go, where I am going to position myself, the timing, etc. And then we adapt,” he said.

“When I go to a place, I just need my mask and sometimes a (monofin) and that's it,” Néry said. “I feel very free.”

CNN’s Marie Barbier contributed to this report.

Franck Seguin is a French photographer based in Paris. Follow him on Instagram. You can also follow freediver Guillaume Néry on Instagram, Facebook and Twitter.

Photo editor: Brett Roegiers