New Delhi, Oct. 31 -- The face, the armpits, the groin.

"Jellyfish are the most unforgiving animals," says the man on the video call. "They always get you in specific places."

This is not the only sting of the long swim in the sea.

"You're cold, you're tired, your shoulders are sore."

From a room with a view of Plymouth harbour, the waters from where Francis Drake and Ernest Shackleton set off on their expeditions, a 56-year-old man is talking to me about grinding. Lewis Pugh insists he's not an explorer, more an endurance swimmer and ocean advocate, yet he's explaining to me the testing journeys through the terrain of the self and the rough roads of nature.

Pugh, a UN Patron of the Oceans, raises awareness through his swims, about p...