A swimmer who tried to back out of diving from the top of a seven-metre board at the last minute saw her jump go horribly wrong. 

A horrified onlooker captured the moment when the swimmer fell at Lava Hot Springs water park in Idaho on film. 

The woman planned to jump off with a friend but had a change of mind at the last second, but was unable to stop the momentum in spite of her attempt to hold on to the railings.

She ends up losing her grip, falling stomach first on to the board below before flipping in the air and landing in the water. 

The clip, which has had over 360,000 views on Youtube, shows the whole incident from her having second thoughts about the jump and trying to back out at the last minute.