How Swarming, Shape-Shifting Drone Sailboats Could Scoop Up Ocean Plastic

The hull bends and curves like a snake in order to control the boat’s trajectory through the water.

Image: Protei design

The world’s oceans are turning into plastic soup, and new research shows we have no idea where 99 percent of that toxic trash—hundreds of thousands of tons—actually is, making it extremely difficult to clean up.

That’s where sailboat drones come in. Using robotic boats is dramatically cheaper than doing manual cleanup—about $3.45 million cheaper, according to Protei, the group behind an open-source, collaborative effort to use drone boats to map the trash near the surface of the ocean and to use that location data to direct cleanup efforts.

The idea of using the sailbot—originally designed to clean up oil spills—to map plastic pollution came up at a session I attended at Google's I/O conference last week that included Protei lead designer Gabriella Levine. I decided to take another look at this utopian idea.

The project got started in 2010 and at this point is still in prototype phase; there have been many different versions over the years, with different applications. As far as trash mapping goes, getting to the scale needed to map the world’s ocean garbage will require a gigantic remote-controlled swarm of nautical drones. Ultimately the idea is to deploy thousands of swarming, meter-long sailboats equipped with sensors and dragging nets behind them to scoop up the garbage. 

Protei’s shape-shifting robotic hull is the project's breakthrough technology, and the design is open source for anyone to use. The hull bends and curves like a snake in order to control the boat’s trajectory through the water. Touted as unsinkable, self-righting, and hurricane-ready, the drone uses wind power, and the latest prototype can tow a payload of under five pounds, the group claims. The vessel would use a custom plastic sensor to locate the trash; the sensor is able to measure “slices” of pollution at various depths.

Protei was originally designed to clean up the BP Deepwater Horizon oil spill. At I/O, Levine explained that the team has also been able to adapt it to measure radioactivity spread from the Fukushima disaster in Japan—basically by adjusting the onboard hardware and sensor configurations.

In the Fukushima experiment, Levine explained that the team basically strapped a modified Geiger counter onto the beast, and then let it loose in the water to map the extent of the radioactivity. Being a prototype, it didn’t quite function the way they had hoped—the radioactive sensing gear was too heavy—but the team said the important part was to get the sensor right. They were able to figure out how to deploy several sensors at different depths, in order to more accurate gauge radioactivity levels.

Image: Cesar Harada/Flickr

Taking a “lean startup” approach, Protei inventor Cesar Harada has bootstrapped or crowdfunded the project up until this point. He's not the only one tackling this ambitious idea. 

Saildrone, an autonomous wind-powered sailboat, successfully sailed from San Francisco to Hawaii, and is currently studying ocean science to help combat climate change. Scout, a solar-powered drone, was the first to attempt a transatlantic sail, from Rhode Island to Spain. (It made it some 1,300 miles before the crew lost communication.) And now there’s a competition underway to send an autonomous sailing drone around the world by 2018. The idea is to use the contest to design an autonomous sailboat that could carry a mini science lab to study the ocean.

Because the technology is both adaptable and cheap, Levine said she hopes to be able to put Protei to use in other situations beyond cleanup: monitoring fisheries stock, studying algae blooms, and checking the health of natural reserves.