A navy ship heading to the Kermadec Islands has sailed into a huge 25,000 square kilometre area of pumice pieces north of Auckland.
It is believed to be from New Zealand's third erupting volcano – the undersea mount Monowai. In the past week both
Mt Tongariro and White Island have erupted.
The navy said the raft – 463 kilometres by 55 kilometres – was spotted by an RNZAF Orion returning on patrol from Samoa.
Lieutenant Tim Oscar, a Royal Australian Navy officer on an exchange with the NZ Navy, saw what he described as "the wierdest thing I've seen in 18 years at sea."
"The lookout reported a shadow on the ocean ahead of us so I ordered the ship's spotlight to be trained on the area. As far ahead as I could observe was a raft of pumice moving up and down with the swell," he said.
"The rock looked to be sitting two feet above the surface of the waves, and lit up a brilliant white colour in the spotlight. It looked exactly like the edge of an ice shelf."
Canterbury, which left Auckland on Wednesday, sailed to the raft to pick up a sample, which would be analysed to determine which volcano they came from.
