The four, aged between 18 and 22, and led by brothers Jethro and Luke Hardinge, are due to depart today on the trip of a lifetime, combining a "big mission" with a chance to raise awareness of alternative transport options.
"I'm definitely not a fan of cars at the moment with the whole oil crisis and I'm trying to push for more alternative transport," said Jethro (22), who studies zoology at the University of Otago.
"While kayaking isn't an option for everyone, it's just another way to get the message out there, just doing something a little bit different."
The trip will see the boys paddling for up to 10 hours a day, carrying their kayaks around dams and past the more dangerous rapids, before they eventually reach the ocean.
They aimed to depart today from the branches of Skippers Canyon and eventually finish their seven-day, 349km trip at St Clair beach in Dunedin.
Luke (20) said the trip, also including fellow Dunedin Polytechnic school of adventure student Anthony Harris (18), and graduate Harrison Greer (19), had required a fair bit of planning, including where they would have to carry their boats, liaising with jet-boat companies as well as deciding what rapids they would take on.
"We do a lot of kayaking obviously, but nothing this big. The first three days are probably going to be the most intense days. The first day there are going to be some grade fours, the second day we've got a five, or maybe two fives, which we might walk around, or we might paddle half of it," he said.
The group had already scouted a number of the more difficult spots - such as the Nevis Bluff grade five rapid - but said plans might change if the river was flowing faster than usual due to the recent rain.
The only support the group will have is when Luke and Jethro's father, Glenn, owner of Kayak Adventures Queenstown and sponsor of the trip, drops off sea kayaks for the transition from white-water kayaks in Cromwell.
For now, they are excited about the trip, but hoping for some fine weather - especially because they cannot fit tents inside the white-water kayaks.
"We're probably going to be sleeping under a tarp from the branches down until Cromwell," Luke said.
"After that, we will hopefully be in tents because we have more room in the sea kayaks."
