Fleet Robotics Develops Magnetic Step-Walking Robots to Clean Ship Hulls at Sea

Boston-based startup Fleet Robotics is developing autonomous hull-cleaning robots designed to reside permanently aboard commercial vessels, using magnetic stepping feet to scrub away organic buildup while ships are underway or at anchor. As reported by TechXplore (https://techxplore.com/news/2026-10-giant-ship-roomba-robots-magnetic.html) via Northeastern Global News, the system aims to replace traditional periodic deep-cleaning in ports with continuous preventive maintenance.

Submerged ship hulls rapidly accumulate biofouling, progressing from microscopic algae to thick colonies of barnacles, seaweed, and mollusks. This biological growth increases surface drag through the water, forcing ships to burn substantially more fuel to maintain transit speeds. According to ocean sensor network Sofar, biofouling-induced drag costs the U.S. shipping industry up to $36 billion annually in additional fuel and antifouling paint expenses.

Beyond fuel inefficiencies, biofouling serves as a major pathway for invasive marine organisms. The International Maritime Organization (IMO) notes that biological transfers have caused significant ecological and economic damage, including the introduction of white spot syndrome virus to New Zealand crustaceans by the Asian paddle crab, and widespread disruption of commercial shellfish beds in the Northeast Pacific by the predatory North Pacific seastar.

Geopolitical bottlenecks and shifting environmental standards have intensified the problem. Idled vessels, such as those held near regional conflict zones in the Middle East, accumulate severe biofouling while stationary, heightening the risk of spreading non-native species when voyages resume. Concurrently, the IMO is preparing mandatory regulations to replace current voluntary guidelines regarding biofouling management.

Fleet Robotics' machine measures approximately one meter (3.3 feet) long and 60 centimeters (24 inches) wide. It consists of two scrubbing units joined by a central bridge. Unlike wheeled or tracked underwater vehicles that roll along surfaces, the robot walks using switchable magnetic feet—lifting one foot, rotating, and setting down the next to navigate complex hull paths. The untethered device operates without Wi-Fi, navigates obstacles autonomously, withstands water pressures at depths down to 40 meters (131 feet), and docks autonomously for recharging.

Engineers at the company emphasize that daily low-intensity cleaning prevents thick growth without stripping protective hull paints, which can accelerate hull corrosion and release toxic antifouling chemicals into the ocean. Timothy Wong, a mechanical engineering and marine science student at Northeastern University who completed a six-month engineering co-op at Fleet Robotics from January to June 2026, helped design the robots' motion compliance system and conducted testing on paint coatings and on an operational vessel at the Woods Hole Oceanographic Institution alongside validation engineer Joshua Batra.