"I always searched for my father where he was born, in Raetihi. But because of all the people who knew him I really found him at Waiinu Beach," he said.
Local people have taken an interest in the unveiling, which pleased Mr O'Connor Whyte because the drownings 61 years ago had a big impact on them.
"We lost one person and they lost five people. It was an incredibly significant event in their lives. Most of them still remember it, as if it just happened yesterday."
After the unveiling and dedication of the rock there was a minute's silence. Then people released helium balloons, which blew east.
Photos were taken and everyone had a small glass of champagne or whisky, with the rest of the whisky poured over the rock.
Then the extended O'Connor family went back to the Waitotara Hotel, where Brian O'Connor and his wife had lived after their marriage, and they had a drink together.
The unveiling was a comfort, but it doesn't end Mr O'Connor Whyte and his sisters' connection with Waiinu Beach.
"We will continue to go up to Waiinu Beach and visit our father," he said.