From source to sea: Lisa Lin and Rory Abbiss empty their flask of Whanganui River water into the waves at Castlecliff at the end of their journey in 2016.
Twenty-two Wanganui Collegiate students are about to embark on one of the toughest journeys of their lives.
Beginning on December 5, the group of Year 12 students (and accompanying adults) will take part in Source to Sea - a gruelling six-day journey down the Whanganui River by foot, canoe and bike.
The journey will begin at Mangatepopo Camp, where the students will make their own dinner and turn in for the night - only to be woken by teachers at midnight for a night-time navigation exercise.
Organiser Rob van Dort said the students have to find their way in the dark to where their bikes will be waiting.
"They're completely left to themselves. We can see them, but they can't see us. We do expect them to get lost - and it's interesting when they get lost, because that's when the natural leaders show their true colours."
Once the students find their bikes, they have a full day of cycling from Mangatepopo to Owhango and on to Whakahoro.
At Whakahoro the students swap their bikes for canoes and paddle to John Coull hut, then Tieke Marae, then to Pipiriki. From Pipiriki they bike to the north mole in Whanganui.
"All the students carry with them a flask of water from the headwaters of the Whanganui River," Mr van Dort said.
"When they get to the north mole they empty it into the sea - this symbolises the name of the trip, which is Source to Sea."
Mr van Dort said the trip was about much more than just travelling from one place to the next. They have minimum intervention from the accompanying adults, so they have to learn to take responsibility for themselves.
"Before we go, they have to organise hiring the canoes and the bikes; they have to organise and cook their own food; they have to pitch their tents; they have to clean and pack all their gear at the end."
Mr van Dort said all the students will struggle with some aspect of the journey.
"Some kids might have never ridden a bicycle for 10km, and now they have to do a whole day on a bicycle. For others, the battle is learning to be patient with the others - they could do the ride in half the time, but they all have to stick together as a group.
"For some kids, it's really tough. Other kids flourish. Some of the kids are just normal kids at school, but put them in a situation like this and they show their leadership qualities."
Students can leave the journey if they are really struggling but in the nine years it's been running, not a single student has pulled out.
Mr van Dort said there was a high demand for places on Source to Sea, but the students were chosen carefully.
He said most had never done a trip like it before.
"For all of them, it's a highlight of their time at Wanganui Collegiate."