Swim from Alcatraz: 'My lung transplant dad is Superman'

In 2008, Gavin Maitland underwent a life-saving double lung transplant.

Five years later he swam from Alcatraz Island to San Francisco accompanied by his son and daughter - a feat that mirrored his journey back from the brink of death.

Gavin, Zander, 13, and Riley, 11, talk about the swim and how their relationships have changed since the illness and transplant.

Produced by the BBC's Anna Bressanin.