These days he uses modern technology to make photographs and the internet to exhibit, communicate with family and friends and make new friends.
"My goal is to capture what the awa is like and strive for nice, crispy photographs.
"Sometimes it's hard work if I am climbing slippery rocks all day. It requires fitness - paddling, creating when not guiding," he said.
The exhibition shared views of te Awa o Whanganui that could be seen only by paddling its reaches.
Mr Ranginui said he was "living my romantic dream of standing in the footprints of my tupuna [grandfathers] and leaving a footprint for the moko to see what koro Charles was up to back in the day."
He said the awa provided so many blessings - physically, spiritually, visually - "and it fills the sense and the soul".
His photographs exude a peaceful beauty. They show just how well he knows the awa.
"It's a threshold to cross and to be transformed by the adventure," he said.
Puna Wai - Water is Life finished yesterday.