The wacky World Vision fundraiser is the brainchild of Waitaki Girls High School year 11 pupil Nikita Coubrough.
Instead of doing the 40-hour famine, Nikita and her friends, Rose Elphinstone-Hayes, Erika Bishop and Gemma Forlong, who are all 15, plan to spend their 40 hours pushing the bathtub, which will sit on a trolley, from Oamaru to Omarama, filling it with money along the way.
They plan to leave Waitaki Girls High School at 6am on Saturday and aim to cover the 108km at 2.75km an hour.
Pushing through the night, the girls hope to arrive in Omarama at 10pm on Sunday.
They will be accompanied by a support crew in the school's minivan and there have been plenty of offers of bath-pushers. School principal Lynlee Smith plans to walk with them for an hour.
Nikita got the idea from her father, who was involved with a Young Farmers Club fundraiser about 20 years ago in which a bathtub was welded on to bikes.
"This is our version," she said yesterday.
She was waiting to get final approval from the New Zealand Transport Agency but expected the only problem would be if the bath needed a warrant of fitness.
"I'm not sure that would go down too good, seeing as there's no airbags," she said.
Staff at Placemakers in Oamaru donated the materials to make the trolley, while the bath, now sporting a pink and purple paint job, was sourced from the Waitaki Resource Recovery Park.
The girls hoped to raised about $2000 from individuals and businesses and have already raised $220 just from visiting four streets in Weston.
Their initiative has attracted loads of support, although "people just look at us and think we're nuts", Erika said.
The girls expected the worst part would be pushing the bath up the steep Otematata Saddle.
