Cellula’s Envoy AUV Achieves 2,000 km Fully Submerged

Cellula Robotics demonstration reinforces viability of hydrogen-powered AUVs for long-endurance offshore tasks

Cellula Robotics has completed a fully submerged endurance demonstration of more than 2,000 km with its Envoy Autonomous Underwater Vehicle (AUV), surpassing the platform’s published performance specification under a representative mission profile.

Conducted entirely below the surface, the trial offers a more realistic measure of operational subsea range than conventional straight-line transit figures. Throughout the mission, the Envoy AUV carried out over 4,000 turns and manoeuvres, each imposing higher energy demand than steady-state travel. As a result, the achieved range provides a more meaningful benchmark of real-world performance in practical offshore conditions.

The milestone was enabled by hydrogen fuel cell technology developed in collaboration with Infinity Fuel Cell and Hydrogen Inc., underpinning the Envoy platform’s extended endurance capability for subsea operations.

“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,” said Neil Manning, CEO of Cellula Robotics. “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 what turns technical capability into offshore results. Longer fully submerged missions can reduce the number of recoveries and relaunches required, support mission continuity, and make better use of vessel time in programmes where logistics, weather windows, and offshore intervention all affect cost and execution.

The Envoy AUV remained on mission for 385 hours and covered 2,023 km submerged on hydrogen fuel cell power 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.

“We are proud to support a milestone that shows what hydrogen fuel cells can enable in real subsea operations,” said William Smith, President & CEO of Infinity Fuel Cell and Hydrogen, Inc. “This result highlights the role fuel cell technology can play in extending endurance, reducing intervention requirements, and supporting more capable long-range autonomous missions.”

While on mission, Envoy’s hydrogen fuel cell system generated water as a by-product, underscoring the lower-emission potential of fuel cell-powered subsea operations alongside their endurance benefits. The demonstration reinforces Envoy’s suitability for missions where endurance directly affects mission continuity, offshore efficiency, and the practicality of sustained subsea deployment.