Kish Proctor, a student who survived the flash flood that killed six of his colleagues and their teacher in New Zealand, has recounted what he went through on Tuesday.

He said he was very excited of the canyoning course in the Tongariro National Park, but the water of the river had risen so fast that they hadn’t have time to react. They were trapped on rocks in the rising river, Proctor said.

The 15-year-old student said that he offered to be the first to jump into the swollen torrent so he could reach the tour guide, but the stream was too strong. He couldn’t reach his instructor and was swept away by the powerful torrent. At some point he managed to get out of the water and was found by two other instructors, who raised the alarm.

"I was sucked under the torrent and there was no way she could have caught me," he said.

"I was being hit left, right and centre, I was wedged in a little cove full of logs."

After he was taken to safety, Proctor found out that some of his colleagues who remained trapped on the rocks weren’t that lucky. Six of them and their teacher died.

The dead students were part of a 40-teenager group taking part in a weeklong canyoning course at the Sir Edmund Hillary Outdoor Pursuits Center in the small town of Turangi.

Canyoning involves navigating the gorge by swimming, clambering over rocks and hiking.

The six students - three boys and three girls - swept away were in a group of 10 and were accompanied by an instructor and a teacher.

The other four students belonging to the group and the instructor managed to survive the flood. One of the students was taken to hospital and is now under treatment.

The tragic accident described as "an unspeakable tragedy" and every family and school's "worst nightmare" by the country’s Prime Minister Helen Clark, prompted the New Zealand Government to order a review into the way local schools carry out field trips and outdoor activities.

The local authorities and the families of the dead students are reportedly making preparations for the funeral of the seven victims. Their bodies are expected to arrive back in Auckland, the country’s main city, tomorrow.