A search and rescue hunt of all the walking tracks, beaches and shorelines resulted in no clues being found as to her whereabouts.
No one had heard or seen from Mrs Philip since August 3 - the day she last spoke to her son, Bevan Philip.
Police also searched Mrs Philip's home and found nothing out of place, although the ranchslider was unlocked - but medication she took daily was not taken on August 4, the report said. Mrs Philip's husband died in 2011 - the couple had been together for 54 years.
Mrs Philip's family told the coroner they thought perhaps she entered the water at a spot where she told them she had scattered her late husband's ashes, the coroner's report states. Mr Matenga said there was insufficient evidence to make any findings about how Mrs Philip died with any degree of certainty, and he has ruled she died in unknown circumstances.
Mrs Philip's daughter Caroline Connor told the Bay of Plenty Times yesterday the family held a memorial service for her mother at Whangamata Club on Friday, which had been attended by members of the mahjong and bowling clubs. The family did not wish to comment further, she said.