The stretch of golf ball-sized pumice rocks was spotted by a New Zealand air force plane about 620 miles north west of Auckland. The rocks stretch for about 10,000 square miles.
A navy ship took scientists to the raft of rocks last Thursday night. Naval Lieutenant Tim Oscar said the rocks appear a brilliant white under a spotlight, like a giant ice shelf.
Scientists say the rocks are likely to have been spewed up in an eruption by an underwater volcano. They do not believe the eruption is connected to the onshore ash eruption this week of another volcano, Mount Tongariro.
Officials say the small rocks pose no danger to shipping.
(New Zealand Navy)
Always thought it was kinda funny how pumice stone is called 'pimp-sten' in Swedish Pimp stone?