"He was towing his boat. He was obviously going fishing and something went awry."
The serious crash unit is investigating.
A death notice in this morning's Herald said Mr Sale was dearly loved by Prue, his partner for 30 "grand years".
"He will be remembered for his smile and his humour by all his brothers - Barry, Ross, Doug and Greg," the notice read.
"Uncle Gudge will be always treasured by Jackson and Renee Sale and by his godchildren. Son of the late Walter and Edna Sale of Hamilton and uncle of Philippa and Jean."
It said Mr Sale had a long and successful career with the Giltrap Motoring Group.
The death notice for Mr Sale invited friends and colleagues to share in a celebration of his life at the All Saints Chapel, Purewa Crematorium at 100 St John's Rd, Meadowbank on Saturday at noon.
Waiheke Island police confirmed Mr Sale's name as the deceased this morning.