An Iranian naval ship seized an American unmanned research vessel earlier this week, before releasing it shortly after US forces scrambled into action.
Late on Monday, the Shahid Baziar – an Iranian Islamic Revolutionary Guard Corps Navy (IRGCN) support ship – was seen towing the US Saildrone Explorer unmanned surface vessel (USV) in international waters.
According to a statement by the US's 5th fleet, American forces then deployed the USS Thunderbolt coastal patrol ship to the scene, as well as an MH-60S Sea Hawk helicopter which was based in nearby Bahrain. That reaction "resulted in the IRGCN vessel disconnecting the towing line to the USV and departing the area approximately four hours later".
In another statement by Vice Admiral Brad Cooper, the Commander of US Naval Forces Central Command, the "IRGCN's actions were flagrant, unwarranted, and inconsistent with the behaviour of a professional maritime force". He added that "US naval forces remain vigilant and will continue to fly, sail and operate anywhere international law allows, while promoting rules-based international order throughout the region".
At seven metres long and driven by solar and wind energy, the USV can be deployed on missions on oceans for up to a year, while being monitored and piloted remotely. Equipped with sensors, radars and cameras, it is able to collect a range of oceanic, navigational, and meteorological data, as well as strategic intelligence.