Rocks likely spewed up in an eruption by an underwater volcano Wellington - Arabstoday A mass of small volcanic rocks nearly the size of Belgium has been discovered floating off the coast of New Zealand, officials said. The floating raft of golf ball-sized pumice rocks, covering almost 10,000 square miles, was spotted by a New Zealand air force plane about 620 miles northwest of Auckland. Scientists taken to the to the rocks Thursday night by a New Zealand navy ship said they were likely spewed up in an eruption of an underwater volcano, a release from the navy said. The floating rocks are a brilliant white, like a giant ice shelf, when seen under a spotlight, navy Lt. Tim Oscar said. Scientist said they don\'t believe the floating pumice is related to the onshore ash eruption this week of a Mount Tongariro, a volcano on New Zealand\'s North Island. Officials say the island of floating small rocks poses no danger to shipping.