But had they not been at their Tekapo hangar it would have taken much longer and the chance of finding anyone alive would have been slim.
Tekapo Helicopters lead pilot Clint Miles told the Herald on Sunday it was fortunate he and colleague Simon Turner were still at the hangar, about five minutes from the Tekapo township.
"If we were at home, it probably would have been another 10, 15 minutes. That time would've made quite a big difference to how things turned out."
They found the first person in the water within about four minutes and 16 minutes later found the rest of the group.
Some had clambered on to Motuariki Island and started a fire to keep warm. Others made it to the shore.
Miles said two survivors had severe hypothermia. Some had been in the water for almost an hour.
The kayakers were all students at Melbourne's Monash University, travelling around New Zealand in campervans. They met at Tekapo on Friday and hired kayaks from Aquanorts.
Police said all were wearing life jackets but the frigid water temperatures were lethal. Company co-owner Kylee Smith said it was a "tragic event".
"Our hearts and our thoughts are with the families."
The survivors have all been discharged from hospital.