In August last year, police helped him ashore after he was unable to get back in his kayak when it capsized off Opotiki in the Bay of Plenty.
He had spent 30 minutes in the water before he was rescued. He was shivering with cold when he reached shore but was not injured.
On Wednesday night, rescuers say Gaastra came closer to death and would not have lasted much longer in the water.
Northland Rescue Helicopter chief pilot Pete Turnbull said the the seas were rough, the wind was blustery and it w as dark, he said.
"I was so proud of the winch team. They did a great job and got the right result," Turnbull said.
Gaastra had activated a personal locator beacon, which an Orion aircraft at Whenuapai airbase detected. The rescue helicopter team dispatched from Whangarei.
It seemed the kayaker was unable to make it through the waves to the beach and a paramedic was lowered in to the water and fitted a harness to him.
"He didn't have long to go and he was severely hypothermic," Turnbull said.
"He'd been bounced around in the swell for about three hours."
Gaastra was flown to Whangarei Hospital and treated before he was released yesterday morning.The Rescue Coordination Centre of New Zealand (RCCNZ) says if it wasn't for his distress beacon the Gaastra may not have survived.
RCCNZ's Dave Wilson said the exhausted man simply "let go" of his capsized vessel when rescuers arrived.
"He did the right thing by carrying a distress beacon. When he was struggling to get ashore through breakers and his canoe capsized, he was able to raise the alarm," Wilson said.
"He saved himself by activating his registered beacon to alert us of his location.
"We urge everyone going out on the water, into the bush, or working in remote locations such as farms, to carry a beacon and make sure it is registered with emergency contact details."
