"One of the mums was telling her little kid - the little kids were running out of the water."
About 45 minutes later, Madz and her mother decided it was safe for a dip.
"We were standing knee deep in the water and we saw two big black shadows just a couple of metres out [from] where the waves were crashing. [They were] just moving along the beach."
The pair left the water and joined others on the beach to watch.
"There was quite a big crowd, everyone just watching them swim past. Nobody was really swimming."
While it was scary, it was also "really cool", Madz said.
"It's not that often you get close to sharks in New Zealand. I'd never seen them out in the wild."
A bronze whaler. Photo / Getty Images
A Coast Guard aircraft sent to investigate the shark sighting found nine in the Matarangi and Whangapoua area about 4pm.
Northern region duty officer Mark Leevers said the sharks had been counted in locations between Matarangi bluff and Motuto Point.
They were between 80m and 100m offshore, he said.
"There are swimmers in the area but the sharks don't appear to be interacting with or sizing up swimmers," he said.
Another member of the Coast Guard said some kayakers had come quite close to a shark but there had been no problems.
Department of Conservation shark expert Clinton Duffy said the sharks were most likely bronze whalers.
"That number of sharks all hanging out together, they're almost always bronze whalers," he said.
"They're not a worry to swimmers. They're fish eaters. If there's some fish blood or something like that in the water they can get aggressive. It's usually towards divers - people they perceive competing towards the same food."
It was not uncommon to see bronze whalers in the Coromandel, Mr Duffy said. "It's pretty common to get the pups in the harbours and shallow inshore areas anywhere between the Hawkes Bay and the North Cape at this time of the year."
Sharks were also seen at Papamoa in the Bay of Plenty at the weekend.
