26 July 2010 Last updated at 05:20 ET

Boat made from plastic bottles completes Pacific voyage

The boat sailed into Sydney harbour after four months at sea

A boat made from thousands of plastic bottles has sailed into Sydney Harbour, completing a four-month voyage that began in San Francisco.

The boat, called the Plastiki, was built using 12,500 plastic bottles.

Its 9,000 mile (15,000 km) voyage aimed to raise awareness of the dangers posed to the environment by plastic waste.

Hundreds of people turned out in Sydney to welcome the Plastiki and its crew of six.

"It has been an extraordinary adventure," said expedition leader and environmentalist David de Rothschild.

Sea of waste

The Plastiki left the US city of San Francisco in March, crossing the Pacific and then travelling via Western Samoa and New Caledonia before arriving in Australia.

It sailed via the Great Pacific Garbage Patch - a sea of waste about five times the size of the UK that sits just below the surface between California and Hawaii.

The vessel is a catamaran, with the thousands of plastic bottles attached with organic glue to two pontoons.

Other parts of the boat such as the sails and the mast are made from recycled materials.

Mr de Rothschild said he and his crew had wanted to raise awareness of the damage caused to the ocean by the disposal of plastic waste.

"We have this addiction to single-use, throwaway plastic, which is choking up the ecosystem," he said earlier this week.

He said that a UN report warning of the dangers posed by plastic waste to the world's oceans was the inspiration for his trip.

The Plastiki will now go on display in Sydney's Maritime Museum.

It was named after the Kon-Tiki, the raft sailed across the Pacific by Norwegian anthropologist Thor Heyerdahl in 1947.

His grandson, Olav, was a member of Plastiki's crew.