Shipbroker Clarksons’ extreme-sports fanatic and Iron Man challenge veteran Stephen Clayton is stepping up another gear to raise money for charity — even as he passes the ripe old age of 60.

Clayton has decided to participate in the Escape from Alcatraz Challenge in aid of Seafarer’s UK.

Enacting an escape from the famous US prison, the challenge involves swimming from Alcatraz Island to San Francisco, followed by a 29-kilometre (18-mile) bike ride.