St John Heretaunga territory manager Brendon Hutchinson said the boy was able to make his way back to shore, while two people nearby attempted to rescue the woman before performing CPR until emergency services arrived about 1.30pm.
"Tragically ,she had already died when St John's paramedics arrived at the beach despite their best efforts to revive her."
Detective Thackeray said conditions at the beach were unusually choppy on an otherwise calm and remote stretch of the coast.
"It's normally quite safe, there are no known rips - it really depends on which direction the wind is coming from."
Mahia Beach Motels and Holiday Park manager Melanie Isherwood said the two rescuers who attempted to save the mother were staying at the camp site. "They are pretty shocked and upset by everything.
"We had a big southerly swell [yesterday] and when we get a southerly it can affect that side of the bay."
Mrs Isherwood said the 47-year-old had two young sons and expected the small community to be in "shock" for some time.
"It's usually such a safe swimming beach, but obviously [yesterday] the conditions turned a bit."
Detective Thackeray said the drowning would hit the community hard and was similar to last year's double drowning near Iwitea.
Last November's double drowning shook the beachside settlement of Iwitea, west of the Mahia Peninsula, when Sage Wi Smith, 22, and Kustom Michael Soljah Blandford, 7, died trying to rescue a relative swept out to sea.
A local woman said the tightknit community would support the family and added that the 47-year-old mother was originally from Napier and had a sister living in Opoutama.
The Lowe Corporation Rescue Helicopter also responded to the incident but were not required.
"Paramedics were already working on her when we arrived but by then she had sadly already passed away," a spokeswoman said.
The woman's body was taken to Wairoa and the death referred to the coroner.
