The bomb was discovered by a member of the public near Putney Bridge in southwest London, just meters (yards) from the starting line of the famous race between rowers from Oxford and Cambridge universities.
The ordinance was found submerged on the Chelsea shoreline Saturday and it was removed by a marine policing unit, the London police force said.
London was heavily bombed in the war, particularly during the Blitz years in 1940 and 1941, as German planes concentrated on civilian and industrial targets. Unexploded devices are still occasionally uncovered.
Oxford won the 163rd boat race by a length and a quarter in 16 minutes, 59 seconds. The course is 4 miles, 374 yards (6.8 kilometers) long.
Cambridge was denied its first back-to-back victories since 1999 but still leads Oxford 82-80 overall after a dead-heat in 1877.
The winning Oxford boat featured the Cook brothers, Jamie and Ollie, along with William Warr, who raced for Cambridge in 2015.
Oxford head coach Sean Bowden said the crew encountered significant difficulties during their preparations for the race.
“It was hard work for a long time,” Bowden said. “It definitely felt like a year where we worked really hard, but nobody ever let their heads get down, and we started to turn the corner in the new year and see our progress.”
Thousands watched the men’s and women’s rowing races, which involve eight rowers and a coxswain and are steeped in tradition.
The men’s race dates to 1829, as a challenge between friends held in Henley-on-Thames and was held irregularly for the next 25 years. The race moved to London in 1836, where it takes place annually around Easter.
The women’s race dates to 1927, but was only raced intermittently until the 1960s.
The Cambridge women broke a four-year cycle of Oxford wins, claiming victory in the 72nd race on Sunday by 11 lengths and in a record time of 18:34.
Cambridge leads Oxford 42-30 overall.
Source: Associated Press