Lewis William Gordon Pugh, OIG, (born 5 December 1969) is a British-South African endurance swimmer and ocean advocate.

In 2010 he swam across a glacial lake on Mount Everest, to draw attention to the melting of the glaciers in the Himalayas and the impact the reduced water supply would have on peace in the region.

Pugh was named a Young Global Leader by the World Economic Forum in 2010 and the United Nations appointed him as the first UN Patron of the Oceans in 2013.

The media coined the term "Speedo Diplomacy" to describe his efforts of swimming in the icy waters of Antarctica and shuttling between the US and Russia to help negotiate the final agreement on the reserve.

In his mid-twenties he returned to England, where he read international law at Jesus College, Cambridge, and then worked as a maritime lawyer at Ince & Co in the City of London for a decade.

[11] On both his Arctic and Antarctic expeditions Professor Tim Noakes, a sports scientist from the University of Cape Town, recorded Pugh's ability to raise his core body temperature by nearly 2 °C in anticipation of entering the freezing water.

[16][17][18] In 2006 Pugh challenged Russia's top cold-water swimmers to a 500-metre race at the World Winter Swimming Championships in Finland.

While swimming through London, Pugh exited the water and made a visit to Tony Blair at 10 Downing Street to call on the United Kingdom to move towards a low carbon economy.

[20] Millions of people from India, China, Pakistan, Bangladesh and Nepal rely on the water, which flows from the Himalayan glaciers.

[22] In July and August 2018, Pugh swam the entire length of the English Channel – the second person ever to do so after Ross Edgley completed the feat a month before during his 1,780-mile circumnavigation swim around Great Britain.

He was greeted on landing at Shakespeare Beach by UK Environment Secretary Michael Gove, who described him as a "modern day hero" and a "brilliant champion for marine conservation zones".

The expedition coincided with some scientists predicting that the North Pole could be free of sea-ice in the summer of 2008, for the first time in thousands of years.

In his autobiography Pugh wrote: "Ironically, global warming played no small part in undermining the entire expedition.

We believed that the greater melting of summer ice would open up large areas of sea and allow us to paddle north at good speed.

[31] And his speech on environmental leadership at the 2008 Business Innovation Forum Conference in the USA was voted as one of the "7 Most Inspiring Videos on the Web" by Mashable, the social media guide.

[33] During his youth Pugh visited many National Parks in South Africa, following his father's desire to teach him to love and respect nature after what he had witnessed whilst serving in the Royal Navy.

He often addresses heads of state and business leaders on the topics of climate change, overfishing and pollution and the need for Marine Protected Areas and low-carbon economies.

[35] In 2008 Pugh founded the Polar Defense Project to campaign for greater protection for the Arctic and a resolution of the maritime boundary disputes.

[36] Pugh was outspoken on the Deepwater Horizon oil spill in the Gulf of Mexico, calling for the criminal prosecution of top BP executives in a feature in Business Day.

In 2018, Pugh was listed as the third-most influential person in the world discussing how to tackle plastic pollution on social media.

He has also been featured by Dr. Sanjay Gupta on Vital Signs on CNN,[42] ADN on France 2, Carte Blanche and Real Sports with Bryant Gumbel.

His father's cousin, Carey Heydenrych, participated in the "Great Escape" from the German POW camp Stalag Luft III during the Second World War.