The Wedgie, WhiteWater World, Australia
Cross your arms and clench your cheeks, because the name of this ride says it all. The Wedgie has no nanny mats and no support tubes. As the trapdoor triggers, it's simply fast flesh on fibreglass as you plummet feet first down a near vertical descent, barrelling through a human-sized helix at speeds up to 41ft per second before smashing into the splash pool down below. This is where the classic "Aussie Cossie" braking system kicks in, when you feel the fast tug on cheeks - giving 'rise' to the slide's bold name. Only the bravest dare do it in Speedos.