An endurance swimmer is taking on a challenge in the Maldives to raise awareness of the effect climate change is having on the South Asian islands.
Mr Pugh was the first person to swim the length of the Thames
Lewis Gordon Pugh, 36, is due to unveil details of his 160km (100 mile) journey later at the Maldives High Commission.
The Maldives is facing potential disasters because of expected rising sea levels caused by global warming.
Last August he became the first person to swim the length of the Thames, to draw attention to the issue in the UK.
Mr Pugh, who is from South Africa, is concerned about the effects of climate change in the polar regions and in the UK, and has also swum in Arctic and Antarctic waters.
He has come into contact with crocodiles, sharks, hippopotami and polar bears.
"I see climate change from a unique perspective. I see its devastating impacts first hand - ice sheets melting, coral dying and lakes disappearing," he said.
"By swimming in these places I want to encourage people to take action. What we eat, the way we travel, how we heat our homes and who we vote for can all have an impact on CO2 levels."
Earlier he undertook a last-minute training swim in the Serpentine Lido, in Hyde Park, in preparation for his swim.