On March 8, 2009, five Chinese vessels shadowed and aggressively maneuvered in dangerously close proximity to USNS Impeccable, in an apparent coordinated effort to harass the U.S. ocean surveillance ship while it was conducting routine operations in international waters.

The Chinese vessels surrounded USNS Impeccable, two of them closing to within 50 feet, waving Chinese flags and telling Impeccable to leave the area. Because the vessels' intentions were not known, Impeccable sprayed its fire hoses at one of the vessels in order to protect itself. The Chinese crewmembers disrobed to their underwear and continued closing to within 25 feet.

USNS Impeccable's master used bridge-to-bridge radio circuits to inform the Chinese ships in a friendly manner that it was leaving the area and requested a safe path to navigate. A short time later, two of the PRC vessels stopped directly ahead of USNS Impeccable, forcing Impeccable to conduct an emergency "all stop" in order to avoid collision. They dropped pieces of wood in the water directly in front of Impeccable's path.

The incident took place in international waters in the South China Sea, about 75 miles south of Hainan Island. It was preceded by days of increasingly aggressive conduct by Chinese vessels:

On March 4, a Chinese Bureau of Fisheries Patrol vessel used a high-intensity spotlight to illuminate the entire length of the ocean surveillance ship USNS Victorious several times, including its bridge crew. USNS Victorious was conducting lawful military operations in the Yellow Sea, about 125 nautical miles from China's coast. The Chinese ship then crossed Victorious' bow at a range of about 1400 yards in darkness without notice or warning. The following day, a Chinese Y-12 maritime surveillance aircraft conducted 12 fly-bys of Victorious at an altitude of about 400 feet and a range of 500 yards.

On March 5, without notice or warning, a Chinese frigate approached USNS Impeccable and proceeded to cross its bow at a range of approximately 100 yards. This was followed less than two hours later by a Chinese Y-12 aircraft conducting 11 fly-bys of Impeccable at an altitude of 600 feet and a range from 100-300 feet. The frigate then crossed Impeccable's bow yet again, this time at a range of approximately 400-500 yards without rendering courtesy or notice of her intentions.

On March 7, a PRC intelligence collection ship (AGI) challenged USNS Impeccable over bridge-to-bridge radio, calling her operations illegal and directing Impeccable to leave the area or "suffer the consequences."

The Chinese ships involved in the March 8 incident included a Chinese Navy intelligence collection ship (AGI), a Bureau of Maritime Fisheries Patrol Vessel, a State Oceanographic Administration patrol vessel, and two small Chinese-flagged trawlers.

U.S. Navy ships and aircraft routinely operate in international waters around the world, and this area is one such location where we operate regularly. Chinese ships and aircraft routinely steam or fly near U.S. Navy ships in this area, however these actions were considerably more aggressive and unprofessional than we have seen, and greatly increase the risk of collision or miscalculation.

Coastal states do not have a right under international law to regulate foreign military activities in the EEZ. The unprofessional maneuvers by Chinese vessels violated the requirement under international law to operate with due regard for the rights and safety of other lawful users of the ocean. We expect Chinese ships to act responsibly and refrain from provocative activities that could lead to miscalculation or a collision at sea, endangering vessels and the lives of U.S. and Chinese mariners.