What do you do if you want to draw attention to the threats faced by the world’s oceans, in particular the huge amount of plastic waste that ends up in them? Easy, you sail across the Pacific Ocean, visiting and documenting environmental hot spots along the way. That, at least, is what the crew of the Plastiki are in the process of doing. The group of six adventurers set out from San Francisco on March 20th, with Sydney, Australia as their final destination. Three and a half months into the 11,000 nautical mile journey, they’re currently about 4,000 miles from the finish line. What makes their odyssey particularly remarkable is their sailboat, the Plastiki – a craft made almost entirely from recycled and/or recyclable plastic that gets the majority of its flotation from approximately 12,500 two-liter plastic bottles.

The material

David de Rothschild, the leader of the expedition, designed the Plastiki as a way of showcasing how waste plastic could be used as a resource. The 60 foot (18 meter) catamaran’s cabin and supporting structure are built mainly from srPET (self-reinforcing polyethylene terephthalate), a completely recyclable material made from woven plastic fibers. Its components are bonded together using an organic glue made from cashews and sugar cane. The sail is made from recycled polyethylene cloth, and the mast is a reclaimed aluminum irrigation pipe.

The bottles

The twin hulls are packed tight with the bottles, which provide 68 percent of the Plastiki’s flotation. Surprisingly, the bottles are completely open to the ocean, with no protective or streamlining skin covering them. Instead, the water actually passes between the bottles. When the boat was being constructed, each bottle had some dry ice placed inside, before having its cap sealed on. As that dry ice turned from solid to gas, its volume expanded, ensuring that the bottle would stay taught, streamlined, and not crumple from the pressure of the water.

Support systems

Power for the boat’s electrical systems comes from a combination of solar panels, two exercise bike generators, and wind and underwater turbines. A human-powered desalinator provides drinking water, collected rain water is used for showers, and the crew’s bodily wastes go into a composting toilet. Because the Plastiki has no refrigerator, fresh greens are being hydroponically grown onboard, using a urine-to-water recovery system.

The philosophy

By undertaking this voyage, de Rothschild and crew are trying not only to get people to see waste as a resource, but also to see the entire concept of waste as flawed and unnatural. When it comes to our thinking on plastics and other materials, it is hoped that the Plastiki will inspire a cyclical “cradle-to-cradle” mindset, replacing the current linear “cradle-to-grave” model.

It truly is a message in 12,500 bottles.