The Plastiki, a catamaran set to cross the Pacific to bring attention to the garbage collecting in mid-ocean, is made entirely of either recycled or recyclable material

The Plastiki is a 60-foot catamaran, kept afloat by 12,000 recycled plastic bottles.

The crew will shove off from San Francisco on a three-month voyage to Sydney, Australia. Its trip was planned by a group called Adventure Ecology.

The Plastiki's sails are made of plastic, rather than cloth. Its mast is an irrigation pipe and its surface is plastic instead of fiberglass.

Crewmembers hope to begin their ambitious journey within weeks.

British environmentalist David de Rothschild, leader of the expedition, poses beside a one-third-size mockup of the Plastiki with his bull terrier, Smudge. He plans to sail with his crew from California to Australia, a distance of about 11,000 miles.

Recycled plastic bottles fill the hull of a prototype of the Plastiki. The actual boat, a 60-foot catamaran, has a hull made from 12,000 bottles.

Nathaniel Corum, cabin architect and programs manager for the Plastiki project, takes a measurement of the boat's cabin.

A worker rolls sheets fabric woven from plastic for the Plastiki when it was being planned in 2009. The fabric, when hardened, was used to build the rigid skeleton, ribs and bulkheads on the Plastiki.