The 29-year-old is retiring to spend more time at home and concentrate on becoming a lawyer. 

"I'm 95 per cent sure that I won't be returning back to rowing," said the Melbourne-based Marburg, who grew up and crafted his rowing skills in Ballarat.

"I've told my coach to ask me again in 2014."

Marburg was a silver medallist in the men's four at the 2008 Beijing Olympic Games.

He competed in his second Olympics in London this year, reach the final in a pair.

He also rowed in five world championships, claiming a silver medal in the men's four in 2009 and bronze 2010 in the eight. 

Marburg announced his retirement during a Victorian Institute of Sport schools visit in Ballarat yesterday.

He and Olympic beach volleyballer Tamsin Hinchley spoke to pupils about their Olympic experiences at Buninyong, Napoleons, Mt Pleasant and Wendouree primary schools. 

Injury is another factor in his retirement.

He suffers from two bulging discs in his back.