Eerily, Wharemate's wife heard his pushbike returning to their Morgan St house and being put away in a shed.
"She thought 'Oh, he is home'," Graham says. "She went out and there was no one there."
The body of Wharemate was found five days later, the newspaper recorded, at "a river beach below Gonville".
After that Wharemate could have a tangi, Graham said, but Williams would only have had karakia. His body was never found and some of his children were whāngai-ed, brought up by other families, and lost touch with their Ngāti Apa iwi.
Descendants remembered the drownings on February 5 to 7, 85 years after they happened. They were welcomed to Whangaehu Marae on Friday, bringing their tūpuna represented in photographs. On Saturday Sonny Poutapu and Aroha Wharemata held a service on the riverside, and the seat was unveiled.
It's a lovely piece of craft, Graham said, and made by George Russell out of red jarrah.
After that the visitors returned to Whangaehu Marae for a hākari, stories about the past and entertainment.
"They are one of the top marae in this country for feeding and looking after people," Graham said. "Their service, their meals, was just another level."