Lifeguard Grace Blackett said at the time that she was looking down at the pool when she noticed something was wrong.
"He did not look like he was in trouble but something in his face told me something was not right," she said.
"I bent down and asked him if he was okay and he didn't answer, so I knew he was really bad.
"Everyone just clicked into action and we got him through until the paramedics arrived."
Ms Blackett called an ambulance and went for oxygen while fellow lifeguards Doug King and Jayesh Mullin reached Mr Darlington and pulled him from the water before his hair even got wet.
Unable to feel a pulse the team quickly drew upon their training to restore his breathing and heart beat.
Mr Mullin grabbed a defibrillator device from the reception area.
Receptionist Jessie Desousa stood beside the lifeguards with her cellphone to relay questions and advice from St John Ambulance staff, who were eight minutes away.
Mr King had started CPR and rescue breathing but with no signs of life, and Mr Jayesh used the defibrillator to regain a heart beat and a pulse returned.
The lifeguards kept administering oxygen and monitoring Mr Darlington's condition until the ambulance and Fire Service arrived.
He was in the Auckland City Hospital intensive care unit for a day and spent a week in both North Shore Hospital and Waitakere Hospital.
Mr King, who has been a lifeguard for 12 years, said it was a relief to know the rescue had a positive outcome.
"You can train your guts out and not really know what the situation is going to be at the time, so I was glad two days later to find out Ken was going to be fine."
Mr Darlington said he could not remember anything of the drama after entering the water at 6am.
"I'd had a bit of indigestion the week before but nothing unusual, no sign of heart trouble.
"I have been doing water walking for eight years to keep fit because I had a triple heart bypass 18 years ago.
"Now the hospital says one of the bypasses I had was partly blocked."
