Oshen, a marine robotics startup, has raised £3.6 million in funding led by Lunar Ventures, with participation from AlbionVC, Twin Track and Concept Ventures, alongside angel investors joining as advisors. Based in Plymouth, Oshen builds a persistent sensing layer for the world's oceans, selling real-time ocean intelligence to navies, national weather agencies and ocean scientists.
C-Stars are 1.2-metre wind- and solar-powered robots designed to be picked up by one person and thrown over the side of any boat. They sail for months without maintenance, transmitting data by satellite, and operate in constellations of dozens of craft spread across hundreds of miles of sea, dispersing for wide-area coverage or converging on a single area of interest. On security missions, they keep a persistent, low-cost watch in waters where sanctioned oil moves on ships with transponders switched off, where uncrewed vehicles operate near cables and pipelines, and where vessels strip fish stocks and run narcotics unobserved. On weather missions, where the ocean's heat is badly under-measured, better surface data means a hurricane's rapid intensification is flagged earlier and evacuations start sooner.
Customers and partners now include the US Navy's Naval Meteorology and Oceanography Command, the Royal Navy, NOAA, the Met Office, Météo-France and VOTO, the Swedish ocean-monitoring body. Building the first 15 C-Stars took three years; production now runs at 15 every six weeks, using a standardising system that lets a new technician assemble parts in less than half an hour. One hundred more are on order, and headcount has grown from seven people in September 2025 to almost 30 today. Constellations have operated across six countries, sold as data as a service, vessel leases, or outright constellation sales.
In September 2025, working under contract with NOAA, three C-Stars penetrated the eyewall of Hurricane Humberto north of St Thomas while the storm was rated Category 5, reporting live data every two minutes through 30-foot waves, a first for any uncrewed surface vessel. That data fed into the National Hurricane Center's official forecast discussion. Other work includes a Cooperative Research and Development Agreement with the US Navy, a Defence and Security Accelerator-backed passive acoustic network trial with ZeroUSV and MarineAI, and a 50-strong constellation in the North Atlantic Subpolar Gyre under a £2 million ARIA project.
The funding will go into scaling manufacturing and into three technical areas where customer demand is growing fastest: passive acoustics for ship detection, protection of subsea critical infrastructure, and anti-submarine warfare.
We're making the ocean's eyes and ears, and we need a lot of them. Seventy per cent of the planet is ocean and we can barely see any of it in real time. That's not a sensing problem any more - the technology works, and it works in the worst conditions on Earth. It's a manufacturing problem. So we've spent the last year turning C-Star production into something closer to a fast-food kitchen than a shipyard: fast, repeatable, and something you can stand up anywhere. There is a version of the next decade where the ocean stops being a dark spot. Not because of one clever sensor, but because there are thousands of cheap robots out there, all the time, telling us what's actually happening. This is our goal at Oshen. We've done step 1 - make world-class robots that have achieved world firsts - now it's time to see the impact a hundred of them can have.
Governments and public institutions increasingly depend on reliable information about the oceans to improve weather forecasting, protect critical infrastructure and strengthen maritime security. Until recently, persistent ocean observation relied on a handful of expensive platforms that could only sample a fraction of the domain. Advances in autonomy and manufacturing are making it possible to replace scarcity with scale. Oshen is among the first companies turning that shift into operational reality.
