Far out in the oceans of the world, away from the continents and even shipping lanes, vast floating seas of plastic garbage form an intractable sort of water pollution, something the bay area’s Project Kaisei is working to combat.

The north Pacific gyre is 700 to 800 miles across, explains Mary Crowley, co-founder of Project Kaisei, but it is not a solid mass of garbage so much as a shallow stew of floating debris.

The north Pacific Gyre is believed to hold the largest plastic Vortex anywhere on Earth, but Crowley observes that there are numerous other gyres across the seas, and each of them have their own growing expanses of floating garbage.

Returning from the Pacific Gyre, the Kaisei sailed under the the Golden Gate Bridge on August 31st. Kaisei is a Japanese word meaning "Ocean Planet."