London Games Olympian Edward Fernon set out on horseback from a farm near Braidwood recreating the long trek of Australian champion racehorse Archer.

Legend has it that Archer was walked all the way from his training base at Nowra to Melbourne to win the first Melbourne Cup in 1861. Archer won the race again the following year.

Over the next five weeks, Fernon, 24, and his horse, also called Archer, will walk 1100 kilometres to Melbourne following the Bicentennial National Trail, arriving in time for the Melbourne Cup on November 6, and along the way he hopes to raise awareness of depression, particularly in rural communities.

At yesterday's starting ceremony, Sydneysider Fernon, his mother, Alex, and a local farmer James Royds - a descendant of Archer's breeders - together unveiled a memorial for Archer on the banks of the Jembaicumbene Creek where the horse was buried in 1872. Fernon achieved a personal best in the modern pentathlon at the Olympics, but he describes all that training as a selfish pursuit, and he knew as soon as he qualified for London he wanted to make use his involvement to make a contribution to the community.

His mother has suffered from depression and Fernon sees parallels between the illness and Archer's long walk to win the Melbourne Cup.

He does not want to see people take the journey of depression alone.

''[I'm] trying raise awareness of depression and trying to encourage people living with the illness to try and get help, and also those who are closest to those suffering the illness to be able to give them support, because over 50 per cent of people living with the illness don't receive medical assistance,'' he said.

Fernon said country people were sometimes reluctant to talk about their depression, or tell people when they were suffering, which was why he was using the ride to fundraise for the Black Dog Institute.

''I'm a firm believer that depression is not a weakness, it's an illness to be dealt with,'' he said.

''People in rural areas experience these terrible natural disasters, [they] have a lot of pressure on themselves and have these periods of depression and for some it can turn fatal.''

Fernon will wend his way to Melbourne, heading to Queanbeyan today and Canberra's Yarralumla horse paddocks in Tharwa tomorrow.

He will then head south through Khancoban, over the Snowy Mountains to Omeo and then to Marysville.

The plan is to be at Healesville on Sunday November 4, and arrive at Flemington racecourse on Melbourne Cup Day.