Lewis Pugh typically starts to plan his next extreme-swimming challenge after just enough time has passed for him to have forgotten how deeply unpleasant the last one was. He opens his atlas – I know! An atlas! – and turns the pages until he finds a body of water that captures his imagination. “I’m flicking through and I think, ‘Can I swim around this cape?’” says Pugh, who is 53, and has been testing the limits of human endurance for 35 years wearing just a silicone cap and a pair of Speedos. “Can I swim down this river? Can I cross this ocean? Can I cross this bay? Where can I shine a light on a place? Where can I tell a story?” When his next venture finally comes to him, Pugh notes, it is never an “aha moment”, but almost always an “err-duh moment” – something glaringly obvious. “I’m agonising, agonising and it’s not quite right and then suddenly” – Pugh claps his hands – “it was right in front of me. ‘Err-duh! Why did I not think of that?’” The atlas has led Pugh, who was born in Plymouth and raised in South Africa, to both the very top of the globe and the bottom of the Earth. At the North Pole, the water was so cold – minus 1.7C – that the cells in his fingers burst and he was in pain for four months afterwards. He has swum 1km in a glacial lake at 17,000ft elevation on Mount Everest (he nearly died) and across the width of the Maldives (OK, that one doesn’t sound too bad). Many people have swum across the English Channel, but he swam the length of it – 348 miles in 49 days in 2018. But Pugh, who is dashing, with sharp cheekbones and a sweep of silver hair, like a telegenic actor who has been cast to play Lewis Pugh in a biopic, insists that these achievements are just clickbait. His real work is done not in the water, but at Downing Street, in the Kremlin, at the Cop summits, convincing world leaders that we need to arrest the degradation of the planet, especially our oceans, before it’s too late. That’s why Pugh considers himself not so much a swimmer or an environmental diplomat, but “a storyteller”. He reasons, “People are never moved by numbers. They are never moved by data. People are moved by stories. It’s been like that since the beginning of time. That’s how we connect, by telling stories.” Finding compelling stories is becoming harder and harder. For one thing, Pugh and two other endurance swimmers – the American Lynne Cox and the Slovenian Martin Strel – have now checked off all of the eye-catching landmarks. Strel specialised in rivers, swimming the length of the Danube, Yangtze and Amazon. Cox swam from America to the Soviet Union in 1987, across the Bering Strait, and was cited by the then Soviet leader, Mikhail Gorbachev, as an example of thawing tensions between the two nations. Pugh, more than a decade younger than Strel and Cox, came along later, “and I was left with all the damn cold stuff,” he smirks. But as Pugh gets older, the main issue is that each time he lowers himself into the water, he has to call on new powers of self-delusion. “It’s the only sport where the more experience you have the harder it becomes,” says Pugh, over a hot chocolate and biscuit in a café in Covent Garden. “Most sports, tennis or golf, the more balls you hit, the better you’re going to become. Not with cold-water swimming. That’s because when you’ve been really, really, really cold, you never quite warm up. It’s deep in your bones. You remember it. “Every single subsequent swim is a monumental mental effort to get back into the water,” Pugh goes on. “So I have to forget about that pain in my hands at the North Pole. I have to forget about that real terror down in the Ross Sea. I have to forget about the anxieties as I was swimming down the tunnel [under the ice sheet] in East Antarctica. I’ve got to forget about the elephant seals down in South Georgia. You’ve got to have a really good reason to get back in. Because it’s really hard to con yourself.” Growing up, Pugh was inspired by two views. The first was from his nursery school, Margaret McMillan in Plymouth, from where he could see ships coming and going from the Sound. “Even as a four-year-old, I’m dreaming that one day I’ll be on one of those ships going somewhere,” he recalls. When he was 10, his parents – Pat, an orthopaedic surgeon in the Royal Navy and honorary surgeon to the Queen, and Margery, a senior nurse also in the Navy – emigrated to Cape Town. From his history classroom at secondary school, Pugh could see Robben Island, where Nelson Mandela was imprisoned until 1982. Pugh’s first serious swim, in fact, was five miles from the mainland to Robben Island and back, when he was 17. “I was a young kid, as thin as you can imagine,” says Pugh. “And I barely made that swim, I was so cold.” But he was proud of what he’d achieved and became a lifeguard, not for the faint-hearted in waters where great white sharks were regular visitors (though less so today, which concerns Pugh). “Cape Town has everything you need if you’re going to be an endurance swimmer,” he says. “You’ve got warm water on the one side, cold water on the other. And you’ve got a lot of really good swimmers who are aggressive in the water.” Pugh lived in Cape Town until last year, when he returned to UK. He’s been staying in London, but thinks he and his wife, Antoinette, a dog trainer, will end up in Dorset or Devon. There were a few reasons behind the move back, but perhaps the main one was that his mother died from Covid during the pandemic. “And I could never leave her, she was so dear to me,” says Pugh. “But if you’re going to be an environmental diplomat, London is probably the place to be. Be under no illusions, we’re in a race against time. So you need to have access to the decision makers.” The plan wasn’t always to effect global change. Pugh studied law at university, first in Cape Town and then Cambridge, and worked as a maritime lawyer in the City for almost a decade. His formative swims, in the 90s, when he was in his early 20s, saw Pugh become the fastest man to swim round Robben Island, then the first person to swim across Lake Malawi. At 23, he swam the English Channel in just under 15 hours. But Pugh was starting to discover he had a capacity for extreme endurance. Years later, a sports physiologist, Tim Noakes from the University of Cape Town, would invent the term “anticipatory thermogenesis” to describe Pugh’s response to cold-water immersion. Uniquely, his body temperature would shoot up to around 38.4C, a mild fever, in advance of entering the water. This enables Pugh to survive in water temperatures that would kill most human beings within 30 minutes. “They talk about anticipatory thermogenesis, this ability to generate heat before an event,” says Pugh. “And it certainly does make a significant difference. What it doesn’t account for is 35 years in the cold. Is it my body? Or my mind? It’s acclimatisation. It’s 35 years of training.” I remember first hearing about Pugh in 2007, when he swam 1km across an open patch of sea at the North Pole, in just under 19 minutes. What he was doing seemed barmy, or at least highly eccentric. Now, of course, it’s hard to find anyone who isn’t evangelical about wild swimming. I ask what he makes of Wim Hof, the Dutch motivational speaker known as the Iceman. “I’ve never met him,” replies Pugh. “A lot of people, I recognise, have started doing his breathing techniques and feel very invigorated and alive and it really works for them. But from a cold-water point of view, it’s very entry-level.” Go on? “So when I was swimming, for example, in the Ross Sea [in Antarctica], the water is minus 1.7C. Now you think, ‘OK, what’s the difference between minus 1.7C and maybe zero?’ It’s a difference between climbing K2 in winter and climbing Snowdon in summer. It’s that big.” Pugh is a big booster of the wild-swimming movement – his favourite thing is taking a dip in the English Channel off south Devon in summer. “My perfect temperature?” he says. “It’s 17C. Not 16. Not 18. 17C.” But there’s a very real difference between what he does on his extreme swims and that. “There are a lot of people who’ve swum now in 2, 3, 4C water,” Pugh continues. “But when you go below it, you are in a death zone. A death zone. Down in Antarctica, I was also dealing with -27C air temperature. Water was slapping up against a side of the Zodiac boat and turning into slush in midair. You’ve got to have a very good reason to be swimming there. Anybody who says to me, ‘I really enjoy the cold…’ They haven’t been cold.” Pugh’s punishing line of work has exacted a toll. Certainly life would have been easier, and more remunerative, had he remained a lawyer. But, as much as Pugh might take a luddite approach to coming up with ideas for his swims, he is rigorous and highly professional when it comes to organising them. It’s then that he turns to Google Earth, and swimming up to two hours a day in training. “There’s a lot of people in my team and they don’t want to be part of something which is a suicide mission,” says Pugh. “I do these things because I value and love life. I’ve got no death wish. I want to swim until the very last day of my life.” How does his wife, Antoinette, feel? “It’s challenging,” he replies, choosing his words carefully. Pugh also has two grownup stepchildren. Does his family ever come on the swims? “My wife’s been on some of the swims, yes. She was on that Ross Sea swim, where it was so dangerous. I wanted her there for support and because it’s a long journey. It takes about six weeks on a boat. The Inuit people say that in every single person there’s a big battle taking place between two wolves – a good wolf and a bad wolf. Which wolf is going to win? And they say it’s the wolf that you feed. At 4am before a swim, I’ve never found it possible to silence the bad wolf.” As for whether the sacrifice is worth it, Pugh can point to some big wins. After a series of swims in Antarctica in 2015, he reached out to Russia – meeting alone with the minister of defence, Sergei Shoigu, in the Kremlin – pushing for the creation of a marine reserve in the fragile Ross Sea. In December 2017, the world’s largest protected wilderness area on land or water came into effect, a move that had been vetoed multiple times by China and Russia. It’s the size of Italy, Germany and France combined. “Everyone said I was crazy, but I knew that cold water is a language that Russians understand,” says Pugh. When we meet, Pugh has not long returned from the Red Sea, which he became the first person to swim across in October, covering 76 miles in two weeks. The swim had some particular challenges, in particular oceanic whitetip sharks and the fact that no one shuts down the Suez Canal, one of the world’s busiest shipping lanes, just because a lone swimmer is coming through. But the main hurdles were geopolitical. Pugh was swimming to raise awareness of the projection that if we heat the planet by 2C – we’re currently at 1.2C – 99% of all living coral will disappear. Making speeches in Saudi Arabia and at the Cop27 summit in Sharm el-Sheikh, Pugh admits, he faced some of the most recalcitrant audiences he has ever encountered. “Unless we drastically reduce emissions, life will die,” he says. “And in Saudi Arabia I said, ‘You can have oil and gas or you can have coral. You can’t have both.’ But we’re currently on track to lose all the coral reefs in the world. I just cannot accept that.” In November, the Egyptian government announced the creation of a 2,000km-long marine protected area called the Great Fringing Reef. Pugh has swum for 35 years and he wants to swim for another 35. He doesn’t want to say where his next swims will be. “I’m not telling you where they are!” he exclaims. “But I see the polar regions and the coral reefs as two ground zeroes of the climate crisis. This is where it’s all happening.” He will go back to his atlas and scour the globe for his next story. As Pugh takes his leave, I tell him that I feel like I’ve been talking to someone from a different era, meaning a Shackleton, a Mallory. Pugh, with a twinkle in his eye, deliberately grasps the wrong end of the stick. “Haha!” he roars. “The future? I hope so.”