A boat built from 12,000 plastic bottles it to set sail this month, with the aim of crossing the Pacific Ocean.
The Plastiki's 100-day journey is intended to test out new materials and highlight the problem of ocean-borne plastic waste.
Its 60-foot hull is built on thousands of two-liter bottles, which are filled with dry ice and capped to increase buoyancy. The hull itself is built from recycled polyethylene terephthalate - a material widely used in bottles - and an experimental fabric based on the same plastic.
Electricity is generated by wind turbines, solar panels - and exercise bikes to be used by the crew.
Plastiki even has its own little garden on board, growing sprouts and herbs, although the designers are a little concerned about the effects of salt spray.
There's a composting toilet, and a rainwater collection system on the cabin roof.
The boat was created by David de Rothschild, who says it will travel up to 200 miles per day on its journey from San Francisco to Sydney.
While he has no sailing experience himself, he says, he's being joined by English yachtswoman Jo Royle and two descendants of Norwegian adventurer Thor Heyerdahl, whose Pacific crossing in the wooden raft Kon-Tiki was de Rothschild's inspiration.