Taking a deep breath, Nery fills his oversized lungs with 8 litres of air, then takes a series of big gulps to pack in another 1.5 litres. He rolls over and, eyes closed to help him concentrate, plunges beneath the sur- face. Legs and torso undulating like a dolphin, he powers himself down with a massive monofin. As he descends, pressure builds on his lungs, com- pressing them so much that when he reaches a depth of 45 metres he is no longer buoyant and spears easily down through the water. When he reaches his goal, 113 metres, the pressure of more than 12 kilograms per square centimetre (around 12 times normal pressure), has shrunk his lungs to the size of oranges.

Nery opens his eyes and grabs a tag from the base of the guide rope to vali- date his feat, flips and kicks upwards, gazing into the dark blue immensity. The colour of the water grows richer, morphing into a deep indigo. Then it turns bright aquamarine as he swims towards the light and the pressure on his lungs gradually relaxes.

Some 25 metres from the surface, four safety divers wait to accompany him on the last, most dangerous por- tion of the dive. Acknowledging them with a small smile, he powers on, swimming until he is buoyant enough to coast the final 5 metres to the surface. He’s been underwater for 2 minutes and 45 seconds.

At the surface, he grins broadly at an official in a support boat to indicate that all is well. He now holds the world record for constant weight freediving.

"When I dive as deep as possible, it’s like discovering a new world, like when humans went to the moon," Nery says.