Sydney - The Pacific Ocean has given birth to a new volcanic island near Tonga, according to ocean-going eyewitnesses. Crew on board a yacht called the Maiken believed they were the first to see a volcanic island forming a day out from Neiafu, Tonga, while sailing towards Fiji in August, the Matangi Tonga news website reported Wednesday.

"One mile in diameter and with four peaks and a central crater smoking with steam and once in a while an outburst high in the sky with lava and ashes. I think we're the first ones out here," a crew member who identified himself as Haken wrote on the yacht's web log.

After ealier leaving the northern Tongan islands group of Vava'u, crew on board the Maiken glimpsed "pumice rafts" floating on the water before they "sailed into a vast, many-miles-wide belt of densely packed pumice".

The crew had earlier encountered huge streaks of pumice after passing Tonga's Late island, according to their web log.

"You might have heard about the sailor's superstition that you should 'never leave on a Friday'. Well, we did and the sea turned to stone, it is hard to get a stronger sign than that," skipper Frederik Fransson said.

Neither Tonga's Ministry of Lands nor the Tonga Defense Service would confirm the creation of a new island.

Separately, fishing boat captain Siaosi Fenukitau reported seeing the volcanic island, the Matangi Tonga website reported.