In between the speedboats, luxury yachts, and wooden fishing boats moored in a Hong Kong marina, a different kind of vessel maneuvers. It looks unassuming, but as the three-meter-long (10-foot-long) uncrewed catamaran moves deftly through the water, it consumes waste floating on the surface in a Pac-Man-like fashion.
Discarded plastic water bottles, juice boxes and cartons travel through a gap in the front of the boat and move up a conveyor belt. A camera photographs the haul, before the garbage is deposited in a collection basket in the center of the boat.
An estimated 33 billion pounds (15 billion kilograms) of plastic trash enter the oceans every year – the equivalent of dumping two garbage trucks worth of waste into the ocean every minute – according to the US nonprofit Oceana. Most of it gets there via rivers and coastlines.
“We have garbage trucks for the land. Why don’t we have something to clean the water?” Sidhant Gupta, the co-founder of the marine-tech startup Clearbot, which developed the boat, told CNN.
Clearbot is trying to change that with its autonomous, solar-powered boats, like the one in Hong Kong which can gobble up 80 kilograms (176 pounds) of waste an hour and carry 200 kilograms (441 pounds) on board.
In the process, it hopes to help the marine industry, which relies heavily on manpower and fossil fuels, evolve. “We’re building the future of boats and ships,” said Gupta.
Decarbonizing “dull, dirty or dangerous” work
Clearbot, which started as a university project, was founded in 2020. Despite Covid-19 shutdowns and a difficult fundraising environment, it’s evolving quickly. Today, it is operating about a dozen boats for various government bodies and corporate clients across Hong Kong, Thailand and India.
The first of its Class 3 vessels, the bigger four-meter (13 feet) boat can collect 200 kilograms (441 pounds) of garbage an hour and carry a load of 1.5 metric tons (3,300 pounds), collecting the waste in a barge towed behind it. It moves at about three knots (3.5 miles per hour).
That includes one collecting waste from the religiously significant but extremely polluted Ganga River, that runs through the city of Kolkata, India. Another operates in Umiam Lake in northeast India, where waste runs downstream from mountainous villages.
What it does with its catch varies by project and region, but it often works with local waste management companies and recyclers.
Its boats can be guided remotely through an online dashboard, or set to run autonomously.
Clearbot has developed algorithms that allow the boat to navigate around obstacles, and to analyze what’s being collected – providing data so that officials can act to stem the flow of waste into waterways.
“Three years ago, this was a PowerPoint presentation,” said Gupta, who studied computer engineering and robotics at the University of Hong Kong. “Today, it’s real.”
But the boats don’t stop at hoovering up waste. According to Gupta, there are many other “dull, dirty or dangerous” jobs that Clearbot’s fleet is capable of.
In Bangkok, Thailand, the company’s boats are clearing algae from lakes, using the same conveyor belt system used for trash, but with a finer mesh material to keep the algae from seeping through it.
In Hong Kong’s Mai Po Nature Reserve, a resting spot for migratory birds, a Clearbot boat has done work to remove the eggs of invasive apple snails – which it can detect using an artificial intelligence model – to stop them from multiplying. For that job, an “agitator,” a type of robotic arm, shakes the eggs off plants, and a nozzle sprays water at the eggs.
The boats can be equipped with a variety of other sensors and tools to map the bottom of waterways, test water quality and collect samples. Cutters can clear invasive plants like hyacinth, and an attachable boom can help clean up oil spills.
The fleet has potential to decarbonize marine operations across a range of uses by replacing fossil fuel-powered boats, said Gupta. Its larger boat has solar panels on top, and an 8-hour battery, while the smaller boat, which can run for four hours, has to be recharged at its docking station.
A robot-boat? ‘Whatevs’
Clearbot isn’t the only company harnessing technology to improve aquatic environments. Entrepreneurs, academics and NGOs across the world are racing to develop innovations – from automated floating trash bins to containment booms to fishlike underwater drones – that clean up waterways and capture more information about what’s happening beneath the surface. Other companies, like Netherlands-based RanMarine Technology, are also working on autonomous waste-collecting vessels.
Robert C. Brears, the founder of water security platform Our Future Water, told CNN that the innovation that succeeds will likely come down to which one can pull ahead in terms of AI technology, to enable the best hardware functionality.
He added that technology that provides better information about water-related issues is sorely needed. “Monitoring and data is really lacking,” he said, despite the impact that water quality and availability has on human health and survival.
Clearbot is now focused on scaling up, and Gupta hopes to have 20 boats deployed by March 2025, and 50 in operation within two years.
He compared the robot boats to the Roomba-like disinfecting robots that operate in many Hong Kong malls, which he said raised eyebrows a few years ago, but are considered commonplace today.
“You should be able to see these in the harbors and think ‘whatevs’ because it’s so normal,” said Gupta. “We want to be ubiquitous.”
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