Waihi Beach north of Tauranga has just reopened after a "little, wee'' one-metre shark sent most swimmers and surfers out of the water earlier this afternoon.
A club member sighted the shark just outside the safe swim flags and alerted lifeguards around 2pm, said Trust Waikato Waihi Beach Lifeguard Service patrol captain Eden Bray.
"We dropped the flags, got all the swimmers out of the water ... to have a wee look, and told all the surfers about it.''
Five people, adults and children, were swimming waist-deep nearby at the time.
Surfers "were not really alarmed'', Miss Bray said.
"A couple of them were obviously nervous ... you know, you hear the word shark and people panic.''
A number of surfers were also advised, and a few chose to leave.
Others kept on surfing and "enjoying the waves''.
"The IRB (inflatable rescue boat) sighted the shark again and confirmed it was just a little wee one, just about a metre long.''
Lifeguards did not know the breed of shark, and it has not been sighted since, she said.
Miss Bray believed a similar incident occurred on Sunday, but could not confirm details.
It was national policy to close the beach following a sighting, she said.
"Like any beach, it happens here on the rare occasion. They're usually small and mind their own business.''