A Canadian company’s submarine drone has travelled more than 2,020km fully submerged, powered by hydrogen fuel cells, and completed a 385-hour mission without surfacing.
Built by Cellula Robotics Ltd, based in Burnaby in the province of British Columbia, the Envoy autonomous underwater vehicle (AUV), formerly known as the Solus-LR, exceeded the platform’s published performance specifications.
The milestone was achieved using hydrogen fuel cell technology. Image: Cellula Robotics.
According to the company, the representative underwater mission offered a more realistic measure of usable range than a simple straight-line transit figure. It also marked a huge step forward for long-endurance robotics.
Neil Manning, CEO of Cellula Robotics, stressed the importance of the achievement: “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.”
Hydrogen-powered mission
Compact and lightweight, the Envoy AUV measures about 8.5 metres in length and one metre in diameter. It has a displacement of about 3,700kg. Smaller configurations are also available for specific mission needs, which makes it adaptable to a range of operational scenarios.
Over the course of the mission, the vehicle executed more than 4,000 turns and manoeuvres, each of which added to its energy demand. This makes the results more relevant for real-world operations, where AUVs are used to map the seabed, inspect infrastructure, and navigate unpredictable underwater environments.
Envoy measures 8.5m in length, 1m in diameter, and has a displacement of approximately 3,700kg. Image credit: Cellula Robotics
During the operation, the Envoy was powered by hydrogen fuel cells from Infinity Fuel Cell and Hydrogen, Inc., a Connecticut-based firm that designs advanced PEM fuel cell and electrolyser systems for aerospace, underwater, and defence applications.
Instead of relying solely on batteries, the fuel cell generated electricity onboard during the mission. It produced only water as a by-product. Manning noted that this proves Envoy is well-suited for long missions where endurance matters.
“That is what makes the endurance meaningful for operators, with the potential for fewer recoveries, more continuous operations and greater efficiency offshore,” Manning continued.
Next-gen underwater tech
Cellula Robotics noted that endurance is critical for operators, as it directly affects cost and efficiency. Longer fully submerged missions mean fewer recoveries and redeployments, reducing downtime and keeping data more continuous.
This is especially important offshore, where operations can be limited by weather, vessel access, and complex logistics. “We are proud to support a milestone that shows what hydrogen fuel cells can enable in real subsea operations,” William Smith, Infinity Fuel Cell and Hydrogen president and CEO, said in a press release.
Smith highlighted the system’s potential. “This result highlights the role fuel cell technology can play in extending endurance, reducing intervention requirements, and supporting more capable long-range autonomous missions,” he concluded.
The Envoy is equipped with a suction anchor, which can attach to the seabed for extended missions in harsh underwater environments. This enables continuous monitoring and data collection, and makes it useful for applications ranging from scientific research to national security.
“The result demonstrates persistent, long-range AUV performance in a real underwater operating context and reinforces hydrogen fuel cells as a practical enabling technology for extended autonomous subsea operations,” the firm said.