Plastic Bottle Boat
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. 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.
"We have this addiction to single-use, throwaway plastic, which is choking up the ecosystem" said David de Rothschild
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.The vessel is a catamaran, with the thousands of plastic bottles attached with organic glue to two pontoons.