Oshen raises £3.6M led by Lunar Ventures to scale its ocean-sailing robot constellations

Oshen, the Plymouth marine robotics company behind the C-Star ocean-sailing robot, has raised £3.6 million (around $5 million) in a round led by Lunar Ventures, with participation from AlbionVC, Twin Track and Concept Ventures alongside angel investors joining as advisers.

Roughly seventy per cent of the planet is ocean and almost none of it is observed in real time. The instruments that do the observing are scarce and costly: navies operate a handful of billion-pound vessels procured over decades, and weather agencies depend on a thin scatter of buoys and satellites. The result is a persistent blind spot over waters where sanctioned oil moves with transponders switched off, where uncrewed vehicles loiter near subsea cables and pipelines, and where the ocean heat that drives hurricane intensification goes badly under-measured.

Oshen's answer is volume rather than sophistication. The C-Star is a 1.2-metre wind- and solar-powered robot light enough for one person to lift and throw over the side of any boat. It sails unattended for months, transmitting by satellite, and operates in constellations of dozens spread across hundreds of miles of sea — dispersing for wide-area coverage or converging on a single area of interest. Customers buy the output as data as a service, as vessel leases, or as outright constellation sales. Founded in April 2022 by Imperial College engineers Anahita Laverack and Ciaran Dowds, the company bootstrapped from a moored sailboat before a small angel round in 2024.

Customers and partners now include the US Navy's Naval Meteorology and Oceanography Command, the Royal Navy, NOAA, the Met Office, Météo-France and Swedish ocean-monitoring body VOTO, with constellations operating across six countries. The first fifteen C-Stars took three years to build; production now runs at fifteen every six weeks, using a standardised assembly system that a new technician can learn in under half an hour. A hundred more are on order, headcount has gone from seven in September 2025 to nearly thirty, and the company recorded £1 million of revenue last year. Its defining result came in September 2025, when three C-Stars working under NOAA contract penetrated the eyewall of Hurricane Humberto at Category 5 strength and reported live data every two minutes through 30-foot waves — a first for any uncrewed surface vessel, and data that 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 fifty-strong constellation in the North Atlantic Subpolar Gyre under a £2 million ARIA project. The new capital goes into manufacturing capacity and three areas where customer demand is growing fastest: passive acoustics for ship detection, protection of subsea critical infrastructure, and anti-submarine warfare. “Governments and public institutions increasingly depend on reliable information about the oceans,” said Mick Halsband, general partner at Lunar Ventures, arguing that advances in autonomy and manufacturing now make it possible to replace scarcity with scale.

Sources

• Soapbox — Oshen unlocks £3.6m in funding led by Lunar Ventures
• EU-Startups — Plymouth-based Oshen raises €4.27 million to scale robot swarms
• Tech Funding News — Imperial College grads' Oshen raises $5M
• Electronics Weekly — Oshen raises funding to track Russian subs