Cellula Robotics Ltd has completed a fully submerged endurance mission exceeding 2,000 km with its Envoy Autonomous Underwater Vehicle (AUV), powered by a hydrogen fuel cell system.
The trial went beyond the AUV’s published performance specification and was carried out using an underwater operating profile designed to reflect real subsea activity. Rather than following a straight-line route, the mission included more than 4,000 turns and manoeuvres, each contributing to higher energy use than steady transit.
Envoy remained underwater for a total of 385 hours, covering 2,023 km during the mission. The system was powered by hydrogen fuel cell technology developed with Infinity Fuel Cell and Hydrogen, Inc.
Neil Manning, CEO of Cellula Robotics, commented, “The significance of this result is not just the distance travelled, but that it was achieved fully submerged in a mission profile that better reflects real subsea operations. That is what makes the endurance meaningful for operators, with the potential for fewer recoveries, more continuous operations, and greater efficiency offshore.”
For operators, endurance is a key factor in translating technical capability into offshore outcomes. Longer fully submerged missions can reduce the frequency of recoveries and relaunches, support continuity of operations, and enable more efficient use of vessel time in programmes where logistics, weather windows, and offshore intervention influence cost and execution.
William Smith, President & CEO of Infinity Fuel Cell and Hydrogen, Inc, added, “We are proud to support a milestone that shows what hydrogen fuel cells can enable in real subsea operations. This result highlights the role fuel cell technology can play in extending endurance, reducing intervention requirements, and supporting long-range autonomous missions.”
During the mission, Envoy’s hydrogen fuel cell system produced water as a by-product, highlighting the lower-emission potential of fuel cell-powered subsea operations alongside their endurance advantages. The result supports Envoy’s suitability for missions where endurance influences operational continuity, offshore efficiency, and the feasibility of sustained underwater deployment.
