The results

Sonardyne’s system performed as planned during the trial. Mini-Ranger 2 mounted easily onto ACUA Ocean’s existing infrastructure, while Ranger 2 software was run from the remote operations centre, showing how the system could be integrated into a USV workflow without adding unnecessary complexity.

The partners completed more than 40 ROV deployments and six days of operations at sea. This included eight launch-and-recovery cycles in a single day. ARGOS reached and inspected the seabed in more than 20 m of water, with up to 35 m of tether deployed.

The campaign included operations in 2 m waves south of Plymouth breakwater, with launch and recovery completed in 1 m waves with winds averaging 18 kt and gusting 20–30 kt.

Demonstrating that the equipment can exceed the operational limits present in most inshore campaigns. Test tasks included inspection of the Poulmic wreck, a seabed feature and a concrete target block in Cawsand Bay.

Using the Mini-Ranger 2 system was critical in being able to initially find and reacquire seabed inspection targets for these trials.

For ACUA Ocean and Forssea Robotics, the trial demonstrated a route to remotely operated subsea inspection from an uncrewed vessel. For Sonardyne, it showed Mini-Ranger 2 supporting USV-based ROV operations where accurate subsea tracking is essential to keeping the vehicle on task.

The impact

“Mini-Ranger 2 was simple to use, and the team were able to operate in a complex environment with multiple robotic systems without it becoming an issue,” says James Cowles, Business Development Director at ACUA Ocean. “Being able to see the USV, ROV and tagged targets on the seabed concurrently on a single screen was really useful, because we had no other way to do that.”

“Mini-Ranger 2 gives operators a flexible way to track, position and communicate with subsea robotics from smaller platforms, including USVs,” says Aidan Thorn, Business Development Manager, Marine Robotics, at Sonardyne.

“Its range, portability and robotics capability make it well suited to emerging operations where ROVs, AUVs and other marine robots need to work from remote or uncrewed vessels. This trial is a good example of that flexibility in practice and of the wider role Mini-Ranger 2 can play across offshore inspection, survey, science and security applications.”

“These trials prove we can open a weather window that conventional crewed vessels cannot work in, giving operators a wider weather window for inspection campaigns,” says Neil Tinmouth, ACUA Ocean CEO. “Just as importantly, running inspection campaigns from an uncrewed surface vessel takes significant cost out of the work – fewer support vessels, fewer people offshore and far less weather-related downtime.”

“All of us at Forssea are hugely proud of this milestone and impressed by Pioneer’s sea-state capabilities,” adds Gautier Dreyfus, Forssea Robotics’ CEO. “Seeing how smoothly the ROV integration and the multiple launch-and-recovery sequences went over the past few weeks was hugely satisfying. My congratulations to the ACUA engineering teams – we are excited to see what comes next.”