Pauline and Alan Hall spotted the whale just outside the entrance to Whangārei Harbour, near Busby Head, on Thursday.
The whale spent a lot of time slapping its tail on the water - a practice known as lobtailing which is used for communication.
“The sound from that was incredible,” Pauline Hall said.
The couple managed to capture photos and a video of the whale’s antics, with Northland whale researcher Jochen Zaeschmar from Far Out Ocean Research Collective later using the video to identify it as a southern right whale.
Zaeschmar said the right whale has a unique blow which goes in two directions, creating a V-shape.
Southern right whales are more commonly seen near New Zealand's subantarctic islands. Photo / Pauline Hall
Southern right whales were once very common but were hunted to near-extinction by commercial whaling.
The New Zealand population is centred on subantartic Auckland Island, and seeing the whales so far north is a promising sign of the species slowly reclaiming its historic range, Zaeschmar said.
“There are thought to be fewer than 100 individuals that reach the mainland and most of those remain in South Island waters. They were once common but are still recovering from commercial whaling. They are very slow to reproduce so it’s a very slow process,” he said.
“A single sighting is not enough to detect any trends but it’s certainly a promising sign, especially with Whangārei Harbour being an important wintering ground in the past.”
The whale was spotted again on Friday and Zaeschmar urged boaties in the area to watch out for it.
Pauline Hall said seeing the whale was a dream come true.
“Every time we have been fishing, we regularly say, ‘wouldn’t it be great to see a whale’. That wish sure came true on Thursday.
“We went home with no fish but our hearts were full seeing this majestic mammal enjoying our beautiful Northland coast.”
She shared her pictures on social media, including the Whale and Dolphin Watch New Zealand Facebook page, where her post got more than 1400 likes.
Southern right whales are mostly black in colour and can easily be identified by lack of a dorsal fin, a V-shaped blowhole spray and white growths on their heads called callosities, according to the Department of Conservation.
They are one of the largest species of whale, weighing around 40 tonnes, with the average male 13 to 15m long and the average female about 16m long. A baleen whale, they feed mainly on krill and small fish.
Far Out Ocean Research Collective is based in the Bay of Islands and focuses on the oceanic megafauna off the northern New Zealand, with aim of generating greater knowledge of the diversity, but also the threats, faced by our marine environment, Zaeschmar said.
Denise Piper is a news reporter for the Northern Advocate, focusing on health and business. She has more than 20 years in journalism and is passionate about covering stories that make a difference.