By VADM David Lewis (USN, Ret.), President of the American Society of Naval Engineers

A meaningful new autonomy milestone emerged at REPMUS26 in Portugal. Plymouth-based Oshen has deployed six 1.2-metre C-Star robotic sailing vessels, each carrying a Systems Engineering and Assessment hydrophone, as a distributed “acoustic picket line.” The company says this is the first time the concept has been tested against live targets rather than as isolated sensors or endurance demonstrations. 

The more important development is the network integration. Ahead of the exercise, Oshen engineers worked with naval counterparts to connect C-Star command software to NATO command-and-control systems; sensor data are being aggregated centrally and shared with participating forces while communications loads are deliberately managed. REPMUS is testing this alongside platforms ranging from tiny autonomous craft to crewed frigates, so the exercise is examining the mixed-force C2 problem rather than merely proving that the boats can collect acoustic data. 

This is directly relevant to Atlantic Bastion and the Type 92/Hybrid Navy sensing layer. The model is a reshapeable field of many inexpensive passive sensors that can help localize a contact from multiple bearings and cue higher-end ASW assets. Oshen explicitly identifies the GIUK Gap as a potential use case and says it currently has three active Royal Navy projects. Eight C-Stars are scheduled for a follow-on U.S. Maritime Big Play experiment in October. 

Assessment: this crosses a useful threshold from “persistent small autonomous sensor” to distributed sensor network operating against live targets and plugged into coalition C2. That architecture is much closer to what Atlantic Bastion ultimately requires: dispersed, attritable sensing nodes feeding a common operational picture rather than autonomous craft operating as stand-alone gadgets.

The caveat is important: this is still an Oshen-led exercise demonstration, not an MoD selection of C-Star.

Main image caption: Alan Jaeger (left, closest to the screen), Naval Surface Warfare Center, Port Hueneme Division acting chief technology officer and U.S. head of delegation to the NATO Joint Capability Group for Maritime Unmanned Systems (JCGMUS), makes opening remarks during the JCGMUS Industry Day and Robotic Experimentation and Prototyping using Maritime Uncrewed Systems (REPMUS) 2026 pre-Initial Planning Conference, Jan. 13 at Fathomwerx Lab at the Port of Hueneme. The two-day event was simulcasted with the U.S. Naval Academy in Annapolis, Maryland, and had more than 60 people participating online via Flank Speed Teams, representing industry, academia, Naval Sea Systems Command program offices and other higher-level Navy offices interested in participating in REPMUS this fall in Portugal.