"We had a fantastic start to the day. They were doing full aerobatics, flips, tumbles and jumps."
Mr Sayer said the fact that a dolphin sighting was fairly routine meant pupils did not protest too much when they had to go back to class. The dolphins were still in the estuary yesterday afternoon.
"They [the pupils] know how it works, it's all pretty routine. But the experience never dulls, there's something quite emotional about it," he said.
Dive! Tutukaka instructor Sophie Roselt had the day off yesterday but did not miss the chance to get in the water when she heard about the dolphins.
She photographed the frolicking trio close-up while hanging on to a buoy.
"The behaviour was mating behaviour, it was play time," she said.
"You swim out and hold on to the buoy line, then they come and check you out. If you're lucky, they're playful. Today they were so playful, we had to get out because we were cold, not because they'd gone away."
Ms Roselt had lived at Ngunguru for 16 years and said she had swum with dolphins in the estuary about 15 times.