The North Shore Coastguard team were about to launch their vessel nearby when they got the call.
Coastguard North Shore volunteer Simon Allard said they located the pair in a few minutes about 4m from the Browns Bay reef where the water is around 3-5m deep.
"It was right on the doorstep," he said.
"We were ready to go. In terms of luckiness, if they had fallen off half an hour later, we might not have been in the area," he said.
They had been capsized for about 20 minutes and had swallowed lots of water, he said.
"They were definitely panicked. They were noticeably hypothermic - very cold, very pale, very quiet."
A senior Coastguard crew member was "quite concerned" about their condition and they were taken to North Shore Hospital, Allard said.
"We quickly wrapped them up in blankets and rushed them into Browns Bay so that the ambulance could take them to hospital to treat their hypothermia as well as ensure there was no water in their lungs which could cause secondary drowning."
St John confirmed they transported two patients in moderate condition to North Shore Hospital's emergency department.
They pulled the hypothermic duo from the water covered in fishing hooks that they had been using to fish with, he said.
The Coastguard crew of six got "lots of thank yous" from the pair.
Allard said the conditions on Monday weren't appropriate for kayak fishing and urged Kiwis to check the conditions and weather forecast before they head out on the water over summer.
It was a similar story for a Wellington man last week, when his kayak flipped and he was swept out to sea by wind and a strong current.
The man launched his boat from Red Rocks in Wellington with plans to fish close to shore but he capsized a few hundred metres off-shore.
In a series of unfortunate events, he capsized a second time, lost his handheld VHF and his lifejacket deflated.
A person noticed him from the shore and alerted police.
He was rescued by the Police Maritime Unit and the Bluebridge ferry Straitsman was asked to help, stopping mid-journey to help locate the man.
