The annual charity Birdman Rally is held at Melbourne's Yarra River, and involves participants flying homemade gliders in front of thousands of spectators.
Contestants jump off a four-metre (13-foot) platform above the river, staying in the air for as long as possible before crashing into the water.
This year's contest attracted 15 competitors, including a man dressed as the Bride of Frankenstein, a woman flying a horse made from balloons and another wearing a pterodactyl costume.
"The strategy was just to basically screw it up as epically as possible," television actor Samuel Johnson said of how he planned to fly his colourful contraption.
"I was really worried about the weight of the 'boob chute' so I decided to kind of ditch that, commit to a forward roll and just never come out of it," he said.
Mr Johnson also raised more than Aus$20,000 (US$15,000) for a cancer charity set up after his sister was diagnosed with the illness, the Australian Broadcasting Corporation reported.