Visitors to Pilot Bay were yesterday treated to the sight of a Southern Right Whale cruising along the shores of Pilot Bay.
Brothers Paul and Hermy Arnold, from Mount Maunganui, said they had never seen anything like it in the harbour before.
"It was a big whale. It attracted quite a large gathering," Paul said.
Department of Conservation senior ranger Yuin Khai Foong said the whale was likely to be larger than 6m long because a Southern Right Whale of that size would still be a dependant calf.
They could easily accidentally crush a person or a boat with a tail or fin slap.
"Adults are around the 14-15m range but can get up to 18m with calves in the 4.5-6m range." He said the callosities on its head and lack of dorsal fin were traits of a Southern Right Whale, also known as a Tohora.
When it blows, the shape of the blow in its signature "V" shape, he said.
Mr Foong said that type of whale was "very happy in shallow water, almost rubbing their belly on the sea floor".
"So to see them in 3-4m of water isn't unusual.
"Once abundant around New Zealand, due to being the "Right" whale to hunt (due to their behaviour and high blubber content making them an easy target and a good yield) they were taken to the brink of extinction.
"They are on the rebound meaning that they are making somewhat of a comeback meaning we are seeing them more frequently around New Zealand's main islands. In terms of Bay of Plenty, there was one there last year so they have been seen in the area before."
Mr Foong said each whale had an individual distinctive callosities patterns so he could be certain it was not the same whale spotted near Leisure Island last year.
It was hard to know why the whale had ended up in the harbour but during winter the species migrate north towards mainland New Zealand, he said.
"They have been known to follow coastlines just off shore so it may be doing that, or it could be feeding."
Mr Foong said the whales usually ate planktonic crustaceans so were not interested in humans as a food source although they could be dangerous.
"There is a risk to us from their size alone. What they consider a small flick of their tail or fins could be a large impact on us as humans.
"They could easily accidentally crush a person or a boat with a tail or fin slap. That is one of the reasons why it is illegal to swim with whales in New Zealand waters."