After weeks of chasing him, Lydia finally speaks to Vitomir Maričić, the Croatian freediver at the heart of the scandal – and he tells his side of the story.

An anti-doping officer tells Lydia that drugs are only considered a problem in freediving on social media, and in podcasts. She learns the problem is bigger, and more complex, and more corrupt, than she realised.   

The CEO of the United States Anti-Doping Agency – and the man who caught Lance Armstrong – has advice for Lydia. It's not what she's expecting.   

Vertical Blue, 2023, the moment the doping scandal erupts. The competition organiser, William Trubridge, recounts his plan to catch the dopers – and Lydia investigates the fallout of a very controversial drugs bust.

Three years ago, travel writer Lydia Gard discovered freediving. An extreme and beautiful sport defined by one objective: to dive as deep as you can on one single breath. It soon became a calling. Then, she stumbled on a darker side of the sport. Rumours that a group of top divers were doping to go deeper.  

Three years ago travel writer Lydia Gard discovered freediving. An extreme and beautiful sport defined by one objective: to dive as deep as you can on one single breath. It soon became a calling. And then she stumbled on a darker side of the sport. Rumours were swirling that a group of top divers were doping to go deeper. So she decided to investigate. Deep Water is the latest Tortoise Investigates series from The Observer.

Lydia travels to Kalamata, Greece, a renowned freediving spot to investigate the doping allegations. What substances are athletes meant to be taking? And what are the risks – to them, and to the sport she loves?