She often feels pangs of guilt and she has given up hope of pursuing her dream job.
Ten years ago, Smith was 16 and part of a year 12 group from Howick's Elim Christian College who found themselves trapped in the Mangatepopo Gorge near Turangi in rising water.
"Ever since it happened I avoid going to the beach alone," Smith told the Weekend Herald.
"I can't deal with open water. I feel terrified if I am by myself, and the first thing I ask is 'Have I gone too far out? Will I be okay?'"
Students Natasha Bray, Portia McPhail, Tara Gregory, Anthony Mulder, Huan (Tom) Hsu, Floyd Fernandes and teacher Antony McClean died in the tragedy on a camp at the Sir Edmund Hillary Outdoors Pursuit Centre (OPC).
Smith and fellow students Kish Proctor, Sarah Brooks and Peter Shih and instructor Jodie Sullivan survived the ordeal.
In an exclusive interview with the Weekend Herald, Smith said she wasn't confident about canyoning, but had wanted to try something new.
"Being with the group gave me confidence to be out there," she said.
When the weather turned during the expedition Ashley attached herself to Sullivan. As the water rose, the instructor made the decision to leave a rock ledge above the Mangatepopo Stream and enter the river.
She told the group, some roped in pairs, to follow at five-minute intervals.
"They were trying to get the confident people to be on either end of the people in the middle. I didn't realise how strong the current was," Smith said.
"I wouldn't have made it without Jodie. But I thought everyone else was okay. I was terrified of water and I wasn't able to cope properly by myself."
Smith still recalls the terrifying screams of school mates as the tragedy unfolded.
"I saw on their faces how scared they were. No matter how hard I tried to help them, I couldn't," she said. "One by one I just saw them go over."
Smith, now 26 and living in Wellington where she is a call centre manager, said she still felt guilt that she "made it and they didn't".
Smith always wanted to join the police or become a forensic scientist but "couldn't focus or grasp anything" after the ordeal.
She suffered nightmares for years and still finds it hard to sleep.
Smith said even 10 years on she constantly thinks of her lost friends.
"I have never forgotten them. I love each and every one of them. I wish they were still here. I know they would be enjoying life and loving every minute of it."
A coronial inquiry in March 2010 found Sullivan was not trained to take groups out of an escape route at a halfway point in the gorge. Other instructors heard claps of thunder in the area and had seen a "brown raging torrent" coming out of the gorge, and that "under-estimation of risks" and "complacency" contributed to the deaths.
In 2009 the Turangi-based OPC was fined $480,000 for its role in the canyoning deaths. At the time the judge said given the weather forecast the group should not have been in the gorge that day and that OPC based decisions on an outdated weather forecast, missing the crucial word "thunderstorms".
Smith doesn't blame Sullivan, saying: "It wasn't solely her fault, but it was an accident that was avoidable".
Fellow survivor Kish Proctor – aged 15 in 2008 – recalled to the
Weekend Herald
how he volunteered to be the first to jump into the rapid torrent and swim a short distance to the safety of a river bank.
He remembers feeling strangely calm as he looked at the rapid torrent.
"Nikki Bray, Natasha's mum, rang me. She said, 'Oh, Tony's down there with the kids, eh? I've been worrying about this weather.' I said, ' Yes, it's been very much on my mind. I guess they won't be doing anything they shouldn't be'."
Tara Gregory's mother, Catherine Linnen, had a "bad feeling", too.
"It was pouring with rain and I remembered saying I hope they are not going to put them in the water on a day like this."
A decade on Linnen still feels robbed after losing her only child.
"Tara was 16. It robbed me of the chance to see her finish school, go to university. It robbed me the chance to have grandchildren," she said.
Tara loved sports, was physically fit and a strong swimmer. But she was scared of the dark.
"She didn't like caving but she was wildly excited about going into the gorge. It was going to be her highlight, she was looking forward to the high wires," Linnen said.
It still rankles for Linnen that Sullivan wasn't held accountable for the loss of life.
"I hold Jodie and the OPC responsible. She wasn't qualified to take them, she hadn't been signed off."
John McClean said he knows his sports and scripture-teaching son put up a "good fight and hadn't just let things happen".
"I wanted to see Tony when the bodies were released. He looked like he'd played a pretty tough game of rugby and had been at the bottom of a few rucks. I was proud of him, he put up a fight."
Jeanette McClean said his death "left a big hole in our hearts". The family had also "lost the potential to have grandchildren".
Today she works at the school her son taught at, taking care of international students.
She also felt Sullivan had been "gung ho" on the day of the tragedy.
"If you are pushing kids into a dangerous situation – you have to know the limits. I feel frustrated she didn't see that."
Andy Bray, Natasha's father, said the tragedy changed his family forever.
"Tash was vibrant and energetic," she said. "She brought so much joy into our household. To have that bright light snuffed out so quickly was devastating."
He said his eldest daughter loved the outdoors and was a natural leader who had a responsible outlook on life.
Bray believed the OPC meant the best but didn't have an acute awareness of the dangers for the students.
"There are moments of anger - and it didn't help to find out the litany of errors."
A coroner's report found the fateful decision to enter the gorge was wrongly left to Sullivan, whose inexperience led her to believe there was no significant danger, despite heavy rain. A police investigation into the tragedy found no evidence of criminal offending.
Linnen believes Sullivan hasn't been made accountable enough for the tragedy.
She understands Sullivan is carrying a big burden, "which is punishment enough", but she hopes one day if she has children of her own "she will understand better how we felt".
The McCleans have never felt anger towards Sullivan.
"Seeing the effect of that tragedy … we could see the pain and sorrow she was going through. Jodie made some bad decisions but we don't want her life to be destroyed by that."
Sullivan attended funerals after the tragedy and had spoken with some family members impacted by the deadly incident.
Sullivan – now a social sciences teacher in the Taranaki – did not respond to calls from the Weekend Herald for comment.
But Hillary Outdoors chief executive Graham Seatter said "not a day goes by" when those at the organisation don't think about the tragedy.
The event had a wide-reaching impact, "including a complete overhaul of our safety systems".
"Our heartfelt thoughts and sympathy remains with the parents and families of the six students and teacher, and all those affected by the event," Seatter said.
Meanwhile, Andy Bray said he wanted the survivors to know they were in his heart.
"I want them to know it's okay to live well and to forgive yourself and move on - choose life."