Bumps: Cambridge’s curious rowing race

Twice a year Cambridge University's rowing clubs hold a four-day boat race called Bumps.

As the city’s river, the Cam, is too narrow to race side by side, up to 18 boats race in single file. Each crew rows at full speed to catch up to and crash into the boat in front of them – to overtake them in the league.

The BBC’s Ben Tavener followed one team from Clare College.