America's Cup: Sir Ben Ainslie starts British bid

Sir Ben Ainslie will begin Britain's bid to win the 35th America's Cup as the opening leg of the series gets under way in Portsmouth.

The preliminary stages are being held in the Solent, where the four-time Olympic gold medallist will lead the British challenge.

Six teams will battle it out at regattas around the world ahead of the final races in 2017.

Duncan Kennedy reports.