Mrs Nicholson said Mr Smith, his niece, a young cousin and Kustom left early on Monday morning to walk to a place on the beach known as the 12 logs - about 2km from the marae.
"It is a big walk even for an adult and the weather was really scorching," said Mrs Nicholson.
Another relative, who asked not to be named, said he was at Iwitea Marae when police drove past followed by an ambulance about two hours later. His two nieces then came running on to the marae, having already alerted a nearby farm manager.
"They were just hysterical, they were saying 'they got drowned, they got drowned'."
The man went to the beach with other relatives to start the search.
Kustom's body was found by Becky Smith's fiance. Mr Smith's body was found about an hour later.
Mrs Nicholson said the drownings were the first in memory at the beach as locals fished there but never swam because of the rips and undertows.
Whanau members last night performed a karakia at the beach.
"It's tragic ... but at least we have their bodies," said Mrs Nicholson.
The family said the unveiling and wedding were likely to go ahead but the family were still deciding on funeral arrangements for Mr Smith and Kustom.