"It's every parent's greatest fear that you realise your daughter is dying and you don't know how to perform CPR," he said.
But a nurse on the beach swam the 15m to 20m to the boat and she began "high-quality CPR" - within four minutes of Jasmine's cardiac arrest.
Within another six minutes a defibrillator had been supplied by local firefighters.
"When that was applied, that brought Jasmine back to life," said Mr Curran. CPR was done for 40 minutes and paramedics took Jasmine by helicopter to Whangarei Hospital where she was assessed before being flown to Starship children's hospital in Auckland.
She spent five weeks there, at first on life support in the intensive care unit.
Jasmine's diagnosis is uncertain as some genetic test results are awaited but she is thought to have the rare condition called CPVT, which sometimes kills the first time it appears.
It is triggered by adrenalin and people with it are advised to avoid competitive sports and strenuous exercise.
A defibrillator device, about half the size of an iPhone, was implanted in Jasmine's abdomen and connected to her heart by wires, and she takes heart medication. She will need further procedures as she grows older to manage the device.
Her surgeon, Kirsten Finucane, said: "She is very lucky to be alive. It was just the resuscitation on the boat that saved her."
She said Jasmine was prone to ventricular tachycardia, in which the heart beats extremely fast, leading to a drop in blood pressure and to potential collapse and sudden death within minutes.
Mr Curran said Jasmine's recovery had been incredible and she had no sign of the brain damage that could have occurred from lack of oxygen to the brain. "That's a miracle.
"We've been blessed with more miracles than we thought were possible.
"We've still got our 5-year-old daughter running and singing and jumping at home as if nothing had happened to her."
Heart trouble
• Jasmine is thought to have the rare heart rhythm disorder, CPVT
• This stands for catecholaminergic polymorphic ventricular tachycardia
• Prevalence unknown, but thought to be one in 10,000 people
• Usually first comes on between age 7-12