A single breath. Lungs inflated with life-giving air, mind focused, cells firing, body propelling through the ocean. How far can a single breath take you? How deep? How long can you last?

Under the ocean surface is freedom, beauty and adventure for divers, and for freediver Jenna Black – unencumbered by air tank or gear – it is also her stadium, her forum, her performance space.

A year ago, Jenna gave up her corporate media job to dedicate herself to freediving, and the results have been extraordinary: she is so good at it, Jenna has been selected as one of four women in the Australian freediving team that will compete at the Freediving World Championships in Lithuania in June.

“It’s my first competition of this size, so my plan is simply to perform to the best of my ability and soak up the experience of being surrounded by the best freedivers in the world,” Jenna says. “It is all very new, and I am still constantly surprised at what I can do.”

At an international competition in Jakarta in February against many of the world’s finest freedivers, the proud Sunshine Coaster came from out of the blue to secure the silver medal, shocking herself and her competitors. But while she is relatively new to competition, Jenna’s love of freediving has long been a lingering, deepening affair.

“Just being in the ocean drew me to freediving initially,” Jenna says. “I have always had that pull, that love of the water and the ocean: growing up on the Sunshine Coast, I have always been close to the beach.

“In the water, you are away from technology, away from the noise and busyness of life. The ocean is my happy place, my place of calm and place of peace.”

PHOTO: @Instagram.com/jenna.black

Jenna, now 36, snorkelled as a child and was the kind of kid who was often diving down to look at something or seeing how long she could hold her breath. Scuba was naturally next for her, and it may well have been in her blood: her parents had met on a scuba trip.

“Then I got the chance to freedive,” Jenna says. “It was immediately appealing because it gave me the ability to be in the ocean and explore it without so much equipment. The free part of freediving was the magic for me to start with. It was the joy without the bulky gear that accompanies scuba.”

Under the sea, Jenna says the environment is as varied as it is breathtaking. Curious marine animals interact. Colourful coral and sea sponges are a visual feast. It is nature, but a world away from the wild places experienced on land.

“Being relaxed and finding that stillness, that calmness of mind, is definitely one of the keys to holding your breath comfortably,” she says. “If you can fully be in the moment and be focused on what you are looking at and what you are exploring, then the breath-hold part becomes secondary to that.

“Obviously, you have to breathe at some point, but recreationally, it is about being there, being so in the moment that you are less focused on needing to breathe.”

But it is in the sport of freediving that Jenna has found the joy of physical challenges and the ability to calm her mind.

The brain makes up two per cent of human body weight, but it takes up 20 per cent of the oxygen breathed and 20 per cent of the energy consumed. This enormous consumption of oxygen and energy fuels many thousands of chemical reactions in the brain every second.

“The more you can calm your mind, the less oxygen you will consume,” Jenna says. “It is pure science, and it is necessary in the sport and for those who want to stay under the water as long as possible. The mindfulness that comes with freediving has been a life changer for me in more than just the way I compete.”

The sport of freediving involves a lot of data. Oxygen uptake, resting heart rates, sleep quality, maximal oxygen consumption all offer up information that are part and parcel with elite sport.

“In the sport, all of that technology and data is excellent for revealing how your body is responding,” Jenna says. “What it cannot measure is how your mind is responding to that breath-hold. The technology will help you become physically capable of completing your best dive possible, but even if your body is capable of that, there is such a mental element that your mind has to be capable of the dive as well.

“And there is no device for mindfulness, visualisation, meditation and breathing techniques, but they are arguably just as important as the physical capability.”

Jenna’s partner in life, business and freediving is Matt Turnbull, an accomplished freediver who will also compete at the Freediving World Championships in Lithuania – representing the United Kingdom. Together with their friend Gonzalo Cortes, Jenna and Matt run OceanSense, providing freediving courses, certification and dive trips locally and internationally.

“It is a gift, this synergy we have,” Jenna says of Matt. “I could not ask for more than to have a partner who doesn’t just understand but who shares my passion.”

Jenna and Matt were away for four months last year, visiting 15 countries. They tie in OceanSense retreats with freediving competitions wherever possible. Being able to find routine, eat well and pack efficiently (her dive gear takes up three-quarters of her bag) are skills Jenna has honed so that she can settle wherever her head rests. But home on the Sunshine Coast is Mount Coolum, the ancient sentinel that has watched over the sea almost since time began.

Australian freedivers spend most of their training time in swimming pools, partly because the continental shelf offshore means there is not enough depth to properly train for freediving. Even if an Aussie diver spends hours on a boat to get out deep enough, they are then in open ocean, which is not conducive to good training conditions either.

So it is to the pool that athletes go, until they get the chance to visit Bali or the Philippines for depth diving training. The world championships are to be held in a pool, which suits Jenna.

“I have trained really hard and I will be ready. In competition, I know I can trust myself now; I can still the voices in my head that tell me to surface and take a breath and listen to the one that says I am okay, that I can stay down a little longer.

“It is a wonderful space, a place of peace, even in the heat of the moment. I actively love everything about it and I remind myself that I get to do this, I get to follow my passion. It really could not be better for me.”