"She looked like she was almost gone, and all of them were hypothermic."
The other two tourists, in a separate kayak, were directed on to Aramoana Spit by tour guide Gordon Douglas, who was in a solo kayak and used a marine radio to call for help.
The crew of a fishing vessel responded to the radio call and plucked the two women who had capsized out of the channel.
They had been clinging to the upturned kayak and were freezing.
"They weren't wearing appropriate clothing for a kayak trip. One of them said she had done some kayaking before on a school trip," Mr Kellas said.
Mr Douglas gave the women a safety briefing as part of the tour, and said they kayaked about 4km without trouble before he turned them back towards Wellers Rock.
"We were getting wind over tide then, so we turned back and that's when the two women had trouble turning. I went to help them, but a wave came and tipped them," Mr Douglas said.
It was the first time a double kayak had capsized on his tour, he said.
The women were taken to Dunedin Hospital.