US SME unveils new anti-submarine warfare system

US-based SME Saildrone has unveiled its largest uncrewed surface vessel (USV) to date, designed to address a growing capability gap in anti‑submarine warfare (ASW). 

An announcement from the company on April 20 says that the 52m Saildrone Spectre USV will be offered in two variants.  

Spectre Silent Endurance is optimised for ASW operations and long-distance missions of up to 8,000 nautical miles, enabled by its hybrid propulsion system. 

Meanwhile, the Spectre Stealth Strike is designed for speed and strike operations, utilising a “wingless configuration” to maintain low visual and radar signature.  

The announcement also stated that Italian shipbuilder Fincantieri will construct the aluminium hulls for the Spectre USVs at its shipyards in Wisconsin, US, with capacity to build up to five vessels per year. Construction is expected to begin shortly, with the first platform scheduled to commence sea trials in early 2027. 

A USD50 million partnership between Saildrone and Lockheed Martin, signed in October 2025, will see the latter integrate its vertical launch systems and sonar arraysinto the Spectre platform. This is intended to support both ASW and strike missions. 

The Spectre USV features a dual electric and diesel propulsion system, offering “near‑silent” electric operation at speeds of up to 12kts.  

Saildrone also produces the Voyager and Surveyor USVs, both of which use hybrid wind, solar, and diesel propulsion  

Saildrone, originally founded in 2012 to gather climate and oceanic data, pivoted to the defence sector several years ago.

The US Navy is the company’s largest customer, having deployed the systems on several task force operations. NATO has also trialled the system during Task Force X in the Baltic Sec in June 2025 to track Russia’s ‘shadow fleet’.