Host Stephen Davis introduces the clip as a recommendation for listeners of his own Antarctic series. The Oceans: Life Underwater podcast is produced by Crowd Network in partnership with Greenpeace and hosted by Hannah Stittfall, a zoologist, wildlife filmmaker, and broadcaster. The promotional clip is taken from episode one. Dan Verhoeven, a free diver with over 20 years of experience and official cameraman of the Vertical Blue competition in the Bahamas, walks the listener through a free dive to 50 metres off Cornwall. He describes lying on the surface to match the ocean's wavelength, the sensation of lungs shrinking as depth increases, the point at which buoyancy disappears and the diver simply falls, and the profound stillness at depth — surrounded by blue-green water, the sounds of the ocean, and a slowing heartbeat. Dan describes being terrified of water as a child and how a moment with his stepfather in a swimming pool turned fear into a lifelong passion. He explains that free diving is the inverse of most extreme sports: success requires slowing the heart rate as low as possible — to 15 beats per minute — rather than elevating it. He mentions that his wife, the UK free diving champion, can hold her breath for 7 minutes. The episode ends with a brief preview of the series' scope: marine biologists, submarine pilots, whale experts, and policy makers across 12 episodes.
