A large area of pumice from an underground volcano has been spotted in the South Pacific Ocean north of New Zealand.
The Defence Force says crew on board HMNZS Canterbury spotted the pumice about 85 nautical miles south-west of Raoul Island on Thursday night.
It says the area of pumice was about 250 nautical miles long and 30 nautical miles wide.
The Defence Force says the ship was brought to a halt so GNS scientists could take samples and then analyse them to see what volcano the pumice came from.
GNS Science says an underwater volcano, Monowai, has been active along the Kermadec Arc and the pumice could be from there.
Scientists on board HMNZS Canterbury say the volcanic activity of Tongariro, White Island and the Kermadec Arc is unrelated.