Key Points:

Teacher Tony McClean, one of the seven to die in the Mangatepopo River tragedy, tied himself to one of the students, a disabled boy, in a bid to save him.

Braced on a ledge in the swollen Mangatepopo River, McClean tied himself to the last teenager left to enter the water and they let go.

The selfless bid to try to save the life of cerebral palsy sufferer Tom Hsu, 16, has prompted many to call the 29-year-old a hero.

The group of school students were on a canyoning trip down the Mangatepopo River when rising flood waters caused by heavy rain swept six students and Mr McClean to their deaths.

The Weekend Herald has learned that rescuers believe Mr McClean's chance of survival would have been "huge" if he had gone alone.

They say Tom would have been like an anchor for Mr McClean.

Being a stronger swimmer than his pupils, Mr McClean would have had a much greater chance of reaching the side of the river before being hurtled over the Genesis Energy dam.

Mr McClean and Tom were the last pair found, floating feet first more than 3km downstream from the plunge over the dam that probably took their lives.

Mr McClean's father, John McClean, said police told him his son and Tom were still bound together.

He said Tom's disability made him the "natural one" for his teacher son to have tried to help.

"When the police lady told me that I thought, 'That's him'," Mr McClean snr said of his eldest child.

Five other Elim Christian College students died on the gorging trip. Four students and Sir Edmund Hillary Outdoor Pursuits Centre instructor Jodie Sullivan survived.

Tony McClean, a surfer and musician who was a youth pastor and tried to live the words of Gandhi, was committed to loving and serving other people in his life - and in his death.

A bond had already formed between Mr McClean's mother Jeanette and Tom, an international student from Taiwan.

As "camp mum" to Elim's overseas students, Mrs McClean had pushed Tom's case to the school, despite uncertain arrangements for funding of the care he would need.

Mr McClean snr said Tom, the only son of two Taiwanese teachers, flourished in the nurturing environment. "He can't speak properly and his hands are no good, but his legs go all right," said Mr McClean snr.

So when the family heard that Tony McClean had been found with Tom tied to him, "we were quite glad".

"In the most traumatic moment of his life, in fact the last moment of his life, he's still doing and saying exactly what he was doing and saying the previous Saturday and the previous week."

Mr McClean snr said his son's body was witness to his struggle to save his own life and Tom's.

"After I had seen him I texted my kids ... I said he wasn't disfigured but he looked like he had been through a pretty tough rugby match.

"I was proud of him. I looked at him and I knew he had struggled _ he would have struggled for those kids, struggled for his own life."

While on the ledge, Mr McClean encouraged the students with prayers and talk of hot showers before sending them off to swim downstream to the waiting instructor.

Miss Sullivan went first with a student, followed by 15-year-old Kish Proctor, who also survived.

Mr McClean and Tom were the last to leave the rocky ledge, and were washed over the dam and down the flooded river.

In a heartfelt letter to the McClean family, survivor Ashley Smith wrote of how Mr McClean "understood us students sooo well" and gave comfort during the ordeal.

"Being terrified of water, I was freaking out but he held me and said, `Don't worry, Ash, you can do this. I know you can because I will be praying for you'," she wrote.

"And right then everyone gathered around me, hugged me and prayed.

"I want you to know Mr McClean was such a special and unique person. I will never forget him."

It is one of the hundreds of tributes the family received this week.

Older brother to Paul, 26, Daniel, 23, and Hannah, 15, Tony McClean went to Auckland Grammar and was a prefect in his final year. He completed bachelor of arts and bachelor of theology degrees from Auckland University and trained as a teacher.

After graduating, he worked at St Thomas School in Kohimarama, Farm Cove Intermediate in Pakuranga and this year joined Elim Christian College.

Interspersed between the work was a season snowboarding in Canada in 2006 and travel last year to work with needy in Nepal and India.

Mr McClean snr, a pastor at Eastview Baptist Church in Howick, said travel crystallised his son's view of the need to live Christianity rather than just talking about it.

Mr McClean said he was immensely proud of his son, but he believed a few heroes had emerged, including Miss Sullivan.

Tony McClean was supposed to be in Christchurch today to be a part of his girlfriend's special day as bridesmaid to her sister.

Instead, Ruth Nixon will brave the ceremony, supported by family, friends and members of the Eastview Baptist Church.

Mr McClean snr said Ruth had decided to continue with her role in the bridal party, and two friends from the church had flown to be with her.

"That's the practical love that comes out of Christianity," said Mr McClean snr. "Too often people don't see that side."