Roger Deakin, wild swimmer and author of Waterlogged

Matthew Parris travels along the Thames to meet Nick Hayes - illustrator and author of The Book of Trespass - to discuss the life of Roger Deakin. They also enjoy a naked swim. Joining them, in his pants, is Patrick Barkham. His new biography of Roger Deakin is published this year.

The producer in Bristol is Miles Warde.