The drone suddenly ascended, and both the South Korean Law Enforcement Boat and the Chinese Fishing Boat, which were engaged in a chase on the sea surface, spotted the drone.
The people aboard the Chinese Fishing Boat didn't pay much attention to military matters and didn't recognize what kind of aircraft it was, nor did they know which country the aircraft belonged to since it bore no identifiable markings.
However, the crew of the South Korean Law Enforcement Boat recognized it almost immediately as a Predator Drone from the US Army, a sight they were accustomed to seeing in South Korean Airspace. What puzzled them, though, was why a US military drone would be in this territorial waters and why there were no US military insignias on the aircraft.