The former St Patrick's College firsts rower captured a silver medal with the Australian men's four that finished second to world champion Great Britian on Saturday night.

Marburg, 25, tried to put the crew's excitement into words after a fairytale Olympic debut at Shunyi Rowing Centre.

"If you think, from where we've come, it's just been the best run; and it's an incredible feeling.

"Olympic silver medallist - if you'd said that to us four months ago, I'd have said you were kidding."

Australia's underdog men's four of Victorians Matt Ryan, James Marburg and New South Welshmen Cameron McKenzie-McHarg and Francis Hegerty led favourites Great Britain with 500m to go to be poised for a major upset,

but got mowed down 250m from the line.

Australia finished 1.28 second behind the UK (6:06.57), with Slovenia third.

Marburg and his crewmates were not originally selected for the priority boat in the men's eight.

They regrouped to win selection in the men's four and then qualified the boat for the Olympics at the last qualification regatta in Poland.

The four blitzed their opening heat in Beijing to dodge a repechage and surged from last place to almost out-gun the British in the semi-final.

Their boat was named Mike McKay, after the Oarsome Foursome crew member, who gave the boys a pep talk prior to the race.

His words of wisdom: "Don't die wondering".

Former Ballarat & Clarendon College rower Sarah Heard became an Olympic finalist in her debut Games campaign.

Heard, who hails from Derrinallum, was a member of the Australian women's eight which finished sixth in final A at Shunyi Rowing Centre last night.