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 15,000 kilometre 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. Expedition leader and environmentalist David de Rothschild said that a UN report warning of the dangers posed by plastic waste to the world's oceans was the inspiration for the trip. 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 Plastiki will now go on display in Sydney's Maritime Museum.