Currently 12,000 to 16,000 2-liter soda bottles are being collected to fill in the twin hulls of their Plastiki vessel. Each bottle with be pressurized using dry ice powder that will sublimate into carbon dioxide gas. If all goes as planned, the vessel will carry four crewmembers on a 11,000 mile journey starting this April from San Francisco to Sydney only to be broken down and recycled at the end of the trip. Apparently, only the masts of the ship are metal, leaving the remaining 90% as recycled material.