Engineers at The Ocean Cleanup have deployed a device that aims to clean up the plastic litter floating between Hawaii and California.

Launched Saturday afternoon, the floating boom is being towed from San Francisco to begin its cleanup efforts at the Great Pacific Garbage Patch, which is about twice the size of Texas and thought to be the world's biggest garbage patch.

Dubbed System 001, the device consists of a 600-metre long plastic float attached to a three metre-deep screen.

Founder Boyan Stat, 24, says he was inspired to work to clean the oceans after going scuba diving in the Mediterranean Sea when he was 16 and seeing more plastic bags than fish.

Years later, Slat and the team at The Ocean Cleanup are launching their first cleanup system out of San Francisco.

"The plastic is really persistent and it doesn't go away by itself and the time to act is now,” Slat told The Associated Press.

Some of the trash his team has found at the Great Pacific Garbage Patch dates back to the 1960s, Slat added.

The device floats along the water and acts like an artificial coastline, trapping any plastic in its path, while allowing fish and other aquatic animals to pass underneath.

Satellite locators and cameras allow The Ocean Cleanup to track the boom, and send boats to clean out the accumulated garbage every few months, and take it to land for recycling.

The organization says they aim to remove about half of the garbage in the Great Pacific Patch within five years, and project that if fleets were deployed around the world they could remove 90 per cent of ocean plastic by 2040.

"I'm the first to acknowledge this has never done before and that it is important to collect plastic on land and close the taps on plastic entering into the ocean,” Slat said. “But I also think humanity can do more than one thing at a time to tackle this problem."