If you're not a Melbourne native, the southern city's Moomba Festival may be something of a mystery. Billed as Australia's largest free festival, Moomba officially begins today and is centred around the Yarra river, with the Birdman Rally being one of the event's major crowd-pullers.

Amphibious Ford Jeeps on the Murray River

What’s the Birdman Rally? A semi-serious competition where individuals attempt to glide the longest distance from an elevated platform into Melbourne’s big brown river. Most would-be Birdmen look to aviation when designing their ‘aircraft’, but we reckon the automotive world has some tips too. Click through the gallery above to check out our highly scientific advice!