The US sent two multi-role unmanned surface vessels (USVs) to its naval bases in Japan, in a move defence analysts said may indicate plans to use drone ships in Washington’s deterrence strategy against Beijing over Taiwan.
The Mariner and Ranger of the US Third Fleet sailed from California to Yokosuka, Japan, last month as part of the US Navy’s Integrated Battle Problem 23.2 exercise (IBP23.2), according to a statement by the US Seventh Fleet, which is headquartered in the Japanese city.

Before arriving in Yokosuka, the Mariner and Ranger stopped over at the Indo-Pacific headquarters in Pearl Harbour in Hawaii, where two smaller USVs – the medium-sized Hunter and Sea Hawk – took part in another rehearsal last year.

The IBP23.2 is an exercise focused on testing the use of USVs together with manned vessels in the Indo-Pacific.

It was the first time the US Navy has sent its driverless ships over such a long distance. According to the US Seventh Fleet, the Ranger was accompanied by the Arleigh Burke-class guided-missile destroyer USS Shoup when it crossed the Pacific.

Lu Li-shih, a former instructor at the Taiwanese naval academy in Kaohsiung, said sending drone boats to accompany warships was a new approach in naval combat, just like the modern air combat tactic of pairing unmanned aerial vehicles (UAVs) with fighter jets during “dogfights”.