These drones look for trash in waterways—and then send sailing drones to clean it up. Together, flying drones and sailing drones are helping to clear rivers of plastic waste and oil spills. March 30, 2021technologyhistoryscoper https://www.fastcompany.com/90618192/these-drones-look-for-trash-in-waterways-and-then-send-sailing-drones-to-clean-it-up