After calling emergency services he drove through water to reach the vehicle.
Inside he found a man and three children, aged 11 and under.
Field grabbed a rock and smashed a window and one by one pulled the children
out of the flooded car.
He put them in the cab of his ute to warm up before a farmer and emergency services arrived to help.
Tamati James Rae, the driver and children's father, was already dead.
Field was later invited to attend Rae's tangi alongside his grieving family.
Field, a diesel mechanic apprentice who left school at 16, shrugged off widespread admiration for his heroics at the time.
"Well yeah, I came back to work and everyone was like congratulations and good stuff," he told the Herald in September.
"As soon as I got back to my place my phone was just going mad. I've had heaps of people Facebook me.
"I guess it's something to be proud of."
Tasman Police District Commander, Superintendent Mike Johnson said Field's actions were a credit to him and his family.
"By taking immediate action I am certain that he saved lives.
"He put others first and saved three young children by demonstrating incredible instinct and practical can-do in a high-pressured situation.
"Police wholeheartedly agree that this young man did a tremendous job and displays the characteristics of true heroism."
One member of local police said the teenager was the epitome of a true hero; super in action and heart.
Another emergency service attendee says Andrew showed maturity and performed heroic actions.
He will receive his Royal Humane Society of New Zealand silver medal in June from the Governor-General, Her Excellency Dame Patsy Reddy.
