In a statement, the Defense Department said five Chinese vessels "shadowed and aggressively maneuvered in dangerously close proximity" to the Impeccable to bother the surveillance vessel while conducting routine operations in international waters, CNN reported.
Crew members aboard the Chinese vessels, two of which were within 50 feet, waved Chinese flags and told the U.S. ship to leave the area, the statement said.
"Because the vessels' intentions were not known, Impeccable sprayed its fire hoses at one of the vessels in order to protect itself," the statement said. "The Chinese crew members disrobed to their underwear and continued closing to within 25 feet."
After the Impeccable alerted the Chinese ships "in a friendly manner" it was seeking safe departure from the area, two of the Chinese ships stopped "directly ahead of USNS Impeccable, forcing Impeccable to conduct an emergency 'all stop' in order to avoid collision," the statement said. Crews then dropped pieces of wood in the Impeccable's path.