New tsunami sirens in Northland had their first real test on Thursday morning and sounded along the east coast about 8am following an earthquake off the Kermadec Islands.
Civil Defence headquarters in Wellington issued an official tsunami warning after the 7.6-magnitude quake which occurred at 7.03am, 160km east of Raoul Island at a depth of 20km.
The Pacific Tsunami Warning Centre in Hawaii sent out a tsunami alert.
Kate Malcolm, of Dive Tutukaka, says the sound had a galvanising effect on residents: the school prepared to head for the marae and others headed for the hills.
Ms Malcolm says the tidal surge was very small compared with previous tsunami waves at Tutukaka and the warning was actually cancelled just before the sirens went off.
Civil Defence in Gisborne and the Bay of Plenty say warnings were effectively sent out. But in other places, surfers could be seen in the water and joggers went running along coastal roads.
Meanwhile, some coastal residents in Auckland say they badly need a tsunami warning system in their region.
Mission Bay resident Marilyn Eales says a warning system would help people prepare if a tsunami was to hit, while Bev Jenkins believes a loud siren would be the best warning system for the suburb.
But Civil Defence says Mission Bay is not a high-risk area because it is sheltered in the harbour and sirens are not always the best method to use.