Their feet are dangling in the freezing cold water and their raft doesn't seem to be heading in the direction they are paddling, but they are all shrieking with laughter.
The children are from Eastfield Primary School in Northampton and they are among the dozens of groups that visit the Frontier Centre near Irthlingborough every year.
Schools, youth clubs and church groups go to the centre for day trips and short breaks and get the chance to try activities ranging from archery to the high ropes course, 30ft up in the air.
The group from Eastfield Primary School are at the Frontier Centre for a three-day stay.
Pupil Kelsie Tyrell, nine, said: "Yesterday we did an assault course and adventure trail and today we have been building a raft and sailing it in the water.
"My favourite activity has been raft building and we got very wet."
Her classmate, Jack Curtis, 10, said: "We had to get the materials and when we had agreed on a plan we started to build the raft. We had a practice run then once we were happy with it we went into the water and our boat sank."
Their teacher, Chris Hill, who stayed on dry land, said the school brings a group to the centre every year.
He said: "It is about being away from home – for the first time for some of them – and about team work. It is also about overcoming challenges.
"Some of the children fell into the water and they couldn't swim but they overcame their fears.
"I think they really enjoyed it as well."
The Frontier Centre this year celebrates its 25th anniversary. It is owned by Barnabas Adventure Centres, an organisation which began life when a group of Sunday school teachers in London became worried that children from the East End were never getting a holiday, so in 1922 they teamed up and took their groups to the East Coast for an adventure.
The Christian charity took ownership of the Frontier Centre in 1998 and since then it has welcomed thousands of young people.
Manager Mike Creese said: "Twenty-five years ago people would have known it as Frontier Camp and when I speak to people they still call it that.
"It began with a few little log cabins right down by the River Nene and it could take about 30 people. They did some activities by the river, but since that time things have developed massively and we now own the whole 122-acre site.
"The main thing we offer is the chance for young people to develop team building skills and to do things outside their comfort zone, which also increases their confidence.
"The whole way we work with them on activities is to push them to do new things, a bit of fear factor. They also encourage each other and what we often find is they cheer on their classmates to come down the climbing tower or climb over the high ropes.
"What it also does is help the teachers as well because they are usually seen as the teacher at the front of the classroom and this helps the children see their teacher in a different light.
"The overnight experience is important because they are away from their parents for a few days with their friends and it is very exciting."
Mr Creese, who has been at the centre for seven years, said: "We have just moved into the new centre office and we've just opened the sports hall. The next stage is to build the swimming pool.
"I really hope we become more and more established as a centre for the local community, Northamptonshire schools and youth clubs.
"We get visits from all over the country but we really want to attract more groups from Northamptonshire."