A ship called the Maersk Launcher towed the 2,000-foot-long device, known as System 001, through San Francisco Bay, under the Golden Gate Bridge, and out to sea, for a final three-day test before deployment. Operation is expected to begin in a couple of weeks. The goal is to remove 50 tons of plastic from the giant mass of trash in the Pacific Ocean in the first year of operation.

The machine is a combination of pipes and netting designed to remove trash from the ocean. A series of four-foot-diameter closed pipes floats on the ocean surface; below the pipes is a 9-foot-wide net. The idea is that the net captures the garbage but avoids trapping marine life by utilizing the flow of the water itself. An anchor keeps the machine moving slowly and allows the water flow to sort the garbage into the net.

Owning the machine is The Ocean Cleanup, a Dutch nonprofit begun by Boyan Slat, a young Dutch diver who was so appalled at the plastic waste he found while diving off Greece that he vowed to make a difference.

The company wants to deploy another 60 such machines, with a goal of removing a full half of the contents of the Patch, which a few weeks ago was estimated to be twice the size of Texas.