Budding scientists who think they can walk on water are being offered the chance to secure a place in the record books.
A national competition to design a pair of self-propelled buoyancy shoes will reach its conclusion as part of Edinburgh International Science Festival.
The festival was launched on Thursday
The contest brings with it prize money of up to £2,000 and the chance to set a new world record.
The event will be held at the city's Commonwealth Pool on Friday, the day after the festival was officially launched by First Minister Jack McConnell.
It is estimated that 10,000 children will attend the festival, which runs at the Assembly Rooms, Botanic Gardens and Royal Museum until 22 April.
The world's first cloned mammal, Dolly the sheep, will be on display at the Royal Museum as part of a display about DNA and cloning.
Other events will give youngsters the chance to find out what it is like to shrink 450,000 times and step inside a human cell at a "bio-bubble".
They can also dig up a life-size Stegosaurus, treat sick animals or climb inside a four-metre nostril and explore the lungs.
The Walking on Water race has been organised by the Edinburgh Science Festival and New Scientist magazine.
It will provide... a hugely entertaining event for young and old alike
Festival director Simon Gage said he was "very excited" about the event.
"As well as the design competition element, which will stimulate engineering and prototype thinking, it will also provide a practical outcome and a hugely entertaining event for young and old alike," he said.
There will be prizes in three categories, as well as the chance to set a new world 40 metres record.
New Scientist editor Jeremy Webb added: "This is a great way to explore the science behind walking on water.
"We are looking forward to seeing both sophisticated and simple designs."