He was rushed to hospital in a serious condition.
Mr Davies' family issued a statement through police tonight.
"While we are filled with sadness at the loss of our dad, the past week has allowed us to say goodbye to him," the statement said.
"It was very comforting for us as a family to be with Dad when he passed and it was very very special."
They had met with Dane Hawker, the man who found Mr Davies last week.
"We met with him and his family yesterday and are filled with appreciation for him finding Dad last Monday. We would also like to thank the North Shore Police, in particular Detectives Liddy Humm and Kellie Osborne, who were both very caring, professional and kind, their efforts brought us comfort during a very difficult time.
"To the many Search and Rescue people who searched in all weathers for Dad, you are amazing and invaluable. Lastly, we thank the many members of the public who offered their support, shared our search on Facebook and sent us messages.
Now is the time for us to say goodbye to Dad."
Police said Mr Davies died peacefully, with his family at his side.
"We are all saddened by this news and our thoughts are with Mr Davies family at this very difficult time" says Inspector Shanan Gray.
Mr Davies found SUB Football. The organisation also issued a statement about his death last night.
"Spending five days out in poor weather took a massive toll on Bill's already fragile health," says Rebecca Stitt.
"We are thankful that his family were able to spend his last days with him, and we are proud to continue his legacy of SUB Football - the game he loved."
Healthy and active most of his life, Mr Davies developed progressive supranuclear palsy, and his health rapidly declined over the last 18 months.
Ms Stitt said football was Mr Davies' passion.
"A lifetime supporter of Everton, Bill converted this passion to his career," she said.
"Bill founded SUB Football 17 years ago, running competitions each summer in the Auckland Domain, Pt Chevalier and Royal Oak, also expanding to Melbourne, Australia. In 2014 he reluctantly handed over management due to his declining health."
SUB Football is a variation on football that encourages fair play, more scoring opportunities and appeals to both new and experienced players.
This summer's competition starts on the 27th October.
The Bill Davies Cup for Outstanding Sportsmanship is named in his honour.