LONDON  - The Aussie activist who halted Britain’s university Boat Race by jumping into the River Thames and swimming between the boats was jailed for six months. Trenton Oldfield, 36, looked surprised as the sentence was passed down at Isleworth Crown Court in London. He was convicted last month of causing a public nuisance. He had leaped into the river in a wetsuit and swam between the boats of Oxford and Cambridge universities in what he claimed was a protest against elitism. It was the first time in the 158-year history of the annual rowing race between England’s most prestigious universities that it has been interrupted by a swimmer. Judge Anne Molyneux said Oldfield had acted dangerously and had failed to show what he was actually protesting about. “You caused delay and disruption to it and to the members of the public who had gone to watch it and to enjoy the spectacle of top athletes competing,” she said. “The rowers had trained for many months. “You had no regard for the sacrifices they had made or for their rigorous training when you swam into their paths.” Oldfield was supported by a group of well-wishers as he arrived at court and posed with a banner reading: “Stop criminalising protest”.