The kids of a small seaside school in Northland have had a close encounter with a pod of orca they'll never forget.
Ngunguru School principal Rick Sayer said children on the deck of the new school building spotted a pod of orca heading up the estuary about 11.30am on Tuesday.
They alerted their teachers, who rang the ''dolphin bell'' — used to signal the arrival of marine mammal visitors — and the entire school walked to the nearby beach.
''It was dead low tide so the kids were just metres from the orca when the pod came through. They went about half a kilometre up the estuary while we were watching, then turned around and came straight back down again past the kids,'' Sayer said.
There was a fair bit of splashing as the visitors cruised up the estuary so he assumed they were hunting for stingrays, ''the lollipops of the orca world''. The whole encounter lasted about an hour.
''It was just incredible. The kids were stunned, they were blown away. Very few of them have been here when orca have come through, it's that rare, and for most of the kids it's the first time they've seen orca. It's something they'll never forget, that's for sure.''
The pod included what appeared to be a calf and a male so huge its dorsal fin was about 1.8m high.
While the students didn't get any maths done, they had a marine biology lesson that schools anywhere in the world would envy.
A video of the encounter captured one of the children exclaiming: ''This is the best day of my life!''
''You just had to stand among the kids to feel the excitement and energy,'' Sayer said.
''I've only seen them three times in 15-odd years so it was pretty special.''
Northland orca expert Ingrid Visser said the family group comprised eight orca including a large male known as Funky Monkey, his younger sister Pickle, now 10 years old, and their mother. There were also two calves, a juvenile and a sub-adult.
The pod was last seen heading down the coast towards Taiharuru; yesterday they were reported off Ruakākā.
Visser said they swam up Ngunguru Estuary to hunt for rays.
''It was quite impressive to see all the kids lined up on the beach watching them,'' she said.
Visser planned to visit the school again soon to talk about the orca the children had seen.
It was typical for the pod to ''bounce up and down'' Northland's coastline. On August 27 they were spotted in Whangārei Harbour, and in June they caused great excitement when they turned up in Marsden Cove Marina.
The same pod had been recorded as far south as Marlborough Sounds and also frequented the west coast. Around this time last year they were hanging out in Hokianga Harbour.
• Funky Monkey, Pickle and an earlier crop of kids at Ngunguru School feature in a 2014 documentary. Search YouTube for "GoPro: Orca Rescue in 4K" to watch it. Call 0800 SEE ORCA if you spot an orca.