"It's just one of those unfortunate accidents. It was a simple piece of water. She just happened to be in the wrong place at the wrong time. They were not foolish and did everything right. They had helmets and lifejackets on," he said.
The friends were not with a commercial rafting group.
None of her companions would have been able to reach Mrs Farrington when she failed to pop out from under the water, Mr Chater said.
"There is a steep wall like a canyon with a very narrow area on both sides. We had to come down from above to reach her. We needed ropes to pull her free. There was nothing anyone could have done," he said.
Speaking from the couple's home in Turangi, Mrs Farrington's brother-in-law, Mark Farrington, said Mrs Farrington had a love of life.
He was unclear what had happened on Saturday but said his brother, Kevin, was shocked and devastated about losing his wife of 35 years.
The couple moved to Turangi two years ago after living in Fiji where Mr Farrington had worked for Air New Zealand.
They moved to Turangi as they loved Lake Taupo and fishing.
Mrs Farrington had been working part-time for the Turangi branch of ANZ.
Mark Farrington said his sister-in-law was a dedicated wife, mother and grandmother.
"She was one of life's loving and caring people."
Arrangements for her funeral were still being finalised.
Mrs Farrington is survived by her husband Kevin, a son and daughter and two grandchildren.
Meanwhile, Mr Chater warned anyone using waterways this summer to be extremely careful, no matter how much experience they had.
"Anywhere where there is a river, there is the chance for mishaps. That was a simple piece of waterway but things can go wrong quickly," he said.
The river was closed while police waited for the water levels to drop to recover her body.
Saturday's accident brings the drowning toll this year to 10.
- DAILY POST