The legacy of his family name made it clear to Philippe Cousteau Jr. from a young age that he would always be linked to the sea.
He learned to swim before he could walk and since then has become a relentless steward of the undersea world.
It was almost inevitable that the ocean explorations by his grandfather, Jacques-Yves Cousteau, would shape his destiny.
But as he says: "It takes more than a birth certificate to be a Cousteau."
Born in the US and educated in Europe, Philippe Cousteau travels worldwide speaking to youth about marine conservation through the non-profit organisation EarthEcho International, which he co-founded with his sister.
His widely-watched documentaries and television programmes continue to educate communities about protecting the oceans.
One on One can be seen each week at the following times GMT: Saturday: 0030, 1630; Sunday: 0430, 2330; Monday: 0300, 1230.