Clare Balding presents live coverage of the 156th Boat Race. More than 250,000 spectators are on the banks of the River Thames to watch the rowing crews from Oxford and Cambridge Universities race each other over the four and a quarter miles from Putney to Mortlake. Oxford have won four of the last five races and will be looking to once again assert their authority over the Light Blues of Cambridge. Commentary comes from Andrew Cotter and Dan Topolski.