Warships from the U.S. Navy sailing off the coast of California in 2019 were swarmed by drones from a nearby Hong Kong cargo ship on multiple occasions, the Navy has revealed. The incidents were all reported between March 30, 2019 and July 30, 2019. Seven different vessels were involved. One of the warships reported in their official memo that the Hong Kong ship was observing them, noting: 'MV Bass Strait likely using UAVs (unidentified aerial vehicles) to conduct surveillance on US Naval Forces'.