The whale spotted by fishermen off the coast of Whanganui on Tuesday was a humpback, the Department of Conservation has confirmed.
Philip Jolly and Mike Silcock were fishing in a 7m boat about 5km off the Whanganui River mouth when they spotted the whale just over 50 metres away and heading north. It stayed near them for about 20 minutes.
Les Judd from DoC said biodiversity ranger Sara Treadgold had gone out with Wanganui Coastguard to try and find the whale, but had been unsuccessful.
"They were keen to take photos of the whale to compare them to our database of whale sightings," Ms Judd said. However, DoC was able to confirm from Mr Jolly and Mr Silcock's photos that the whale was a humpback (Megaptera novaeangliae), approximately 14m long.
"Humpbacks grow up to 15m long, so this was definitely an adult."