The Impeccable Incident – A Legal Perspective

On March 8, 2009, the USNS Impeccable was operating 75 miles south of Hainan island belonging to China, while it was using its sonar array to monitor Chinese submarines near the island of Hainan a major submarine base. It was engaged by several Chinese ships. According to the Pentagon, the unarmed Impeccable was shadowed by five Chinese ships, including a Bureau of Maritime Fisheries Patrol Vessel, an Oceanographic Administration patrol vessel, a Chinese naval ocean surveillance ship, and two small Chinese trawlers, which manoeuvered close to the Impeccable, with two of the ships coming as close as 50 feet (15 m), waving Chinese flags, and ordering the Impeccable from the area. The civilian crew of Impeccable sprayed water at one of the nearest Chinese ships; the Chinese sailors stripped down to their underwear and their vessel closed in to within 25 feet of the American ship. Shortly after the incident, the Impeccable radioed the Chinese crews, informing them of its intentions to leave the area, and requesting a safe pass to travel. When trying to leave the area, however, the two Chinese trawlers stopped directly in front of the Impeccable, forcing it to do an emergency stop to avoid a collision. Once the Impeccable got underway, the crew aboard one of the Chinese ships used a grappling hook to try to snag Impeccable's towed sonar array.

This was the latest in a string of incidents involving the Impeccable and Chinese vessels. On March 5, 2009, a Chinese frigate approached Impeccable, crossing 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 flyovers of Impeccable at an altitude of 600 feet (180 m) and a range from 100–300 feet (30–90 m). The frigate then crossed Impeccable's bow again, this time at a range of approximately 400–500 yards, without notifying Impeccable its intentions.

On March 7, a Chinese intelligence collection ship contacted the Impeccable over bridge-to-bridge radio, informing her that her operations were illegal and directing Impeccable to leave the area or "suffer the consequences."

The United States lodged formal protests following the incident.

This is the second time that the Chinese warships have been involved in a controversial incident in the past couple of months. In the middle of January 2009, an Indian submarine played "cat-and-mouse" with two Chinese warships off the coast of Africa before it was spotted and “forced” to surface in the latest round of cold-war games between the two countries.

Neither India nor China officially confirmed or denied the reports. But Chinese media reported the incident and an Indian Navy source said “we do not discuss our deployments”.

Why were the Chinese provoked? In order to understand the Chinese apprehensions it is necessary to understand the background of this vessel and its operations.

The ship USNS Impeccable is an Impeccable-class ocean surveillance ship aquired by the US Navy in 2001 and assigned to the Navy’s Special Missions Program.[1] Surveillance Towed Array Sensor System (SURTASS) is a towed array sonar system of the US Navy. SURTASS systems developed in the 1980s were deployed on Stalwart-Class Ocean Surveillance Ships and were passive, receive only sonar systems. The array was towed miles behind the ships and were designed for long range detection of submarines.

SURTASS Low Frequency Active (LFA) systems were designed for long range detection using both active and passive sensors. The active component transmits an audio signal between 100 Hz and 500 Hz from an array suspended below the ship while the passive SURTASS array is towed miles behind to receive the signal. LFA has been criticized for its potential to injure undersea wildlife.

SURTASS Twin-Line consists of either the long passive SURTASS array or the Twin-line array consisting of two shorter passive arrays towed side by side. The Twin-line Engineering Development Model was installed on USNS Assertive, and the first production model was installed on USNS Bold. Both ships are no longer serving as SURTASS units. As of 2006, SURTASS was deployed on T-AGOS 19 Victorious class and T-AGOS 23 Impeccable class Small Waterplane Area Twin Hull (SWATH) vessels as well as MV Cory Chouest, the developmental ship for SURTASS LFA.

China alleged that the US Navy ship involved in a confrontation with its vessels off the southern island of Hainan violated international and Chinese law. Admittedly, the USNS Impeccable was 75 miles off the coast of Hainan, much beyond the territorial waters (12- nautical miles) of China. According to Beijing the ship was conducting activities within the waters of its exclusive economic zone.

The purpose of this paper is to analyze key legal issues from the perspective of international law The question that arises is whether the activities conducted by USNS Impeccable, viz. surveillance or gathering intelligence in the Exclusive Economic Zone (EEZ) was in violation of international law?

The Law of the Sea: The 1982 Convention on the Law of the Sea or United Nations Convention on the Law of the Sea (UNCLOS III) adopted on 30th April 1982 for the first time provided that coastal states had sovereign rights in a 200-nautical mile zone – called the Exclusive Economic Zone (EEZ) with respect to natural resources and certain economic activities and exercise jurisdiction over marine science research and protection of the environment.

“Article 56 of UNCLOS 1982 provides for the rights and duties of the coastal state in the Exclusive Economic Zone –
1. In the exclusive economic zone, the coastal State has:
(a) sovereign rights for the purpose of exploring and exploiting, conserving and managing the natural resources, whether living or non-living, of the waters superjacent to the seabed and of the seabed and its subsoil, and with regard to other activities for the economic exploitation and exploration of the zone, such as the production of energy from the water, currents and winds;
(b) jurisdiction as provided for in the relevant provisions of this Convention with regard to:
(i) the establishment and use of artificial islands, installations and structures;
(ii) marine scientific research;
(iii) the protection and preservation of the marine environment;
(c) other rights and duties provided for in this Convention.
2. In exercising its rights and performing its duties under this Convention in the exclusive economic zone, the coastal State shall have due regard to the rights and duties of other States and shall act in a manner compatible with the provisions of this Convention.
It is important to note that the coastal states do not enjoy complete sovereignty over the EEZ, but only sovereign rights for the purpose of exploring and exploiting, conserving and managing the natural resources and jurisdiction with regard to establishment and use of artificial islands, installations and structures; marine scientific research; the protection and preservation of the marine environment. The coastal states cannot in any manner impede the freedom of navigation, which China sought to do in this case.

Article 58 of UNCLOS 1982 stipulates the rights and duties of other states in the Exclusive Economic Zone –
1. In the exclusive economic zone, all States, whether coastal or land-locked, enjoy, subject to the relevant provisions of this Convention, the freedoms referred to in article 87 of navigation and overflight and of the laying of submarine cables and pipelines, and other internationally lawful uses of the sea related to these freedoms, such as those associated with the operation of ships, aircraft and submarine cables and pipelines, and compatible with the other provisions of this Convention.
2. Articles 88 to 115 and other pertinent rules of international law apply to the exclusive economic zone in so far as they are not incompatible with this Part. (These provisions relate to the High Seas)
3. In exercising their rights and performing their duties under this Convention in the exclusive economic zone, States shall have due regard to the rights and duties of the coastal State and shall comply with the laws and regulations adopted by the coastal State in accordance with the provisions of this Convention and other rules of international law in so far as they are not incompatible with this Part.”

Article 301 of the 1982 Convention also provides: “In exercising their rights and performing their duties under this Convention, States Parties shall refrain from any threat or use of force against the territorial integrity or political independence of any State, or in any other manner inconsistent with the principles of international law embodied in the Charter of the United Nations.”

Can the Impeccable’s mission be construed as a hostile act or be considered in any manner as a threat to the territorial integrity or political independence of China? The US ship, assuming that it was indulging in surveillance or intelligence gathering, was firstly unarmed and was not part of any naval fleet or battle group. Hence, it would be stretching the law, particularly Article 301 a bit too far to bring its alleged surveillance activities within its ambit.

From a purely legal perspective, although aircraft and ships are expressly prohibited from spying in the twelve mile territorial zone, they are not so prohibited from engaging in spying in the EEZ. Indeed, Article 19(2) (a), applicable to the territorial zone, contains virtually the same provision as Article 301 requiring states to refrain from any threat or use of force. In addition, however, Article 19(2) (c) then expressly prohibits intelligence-gathering activities. This suggests that the drafters and state signatories meant to distinguish between (i) spying and “any threat or use of force against the sovereignty, territorial integrity or political independence of the Coast state” and (ii) spying in the territorial zone and the EEZ or high seas. Had the states wanted to make spying in the EEZ illegal, they could have included an express prohibition against it just as they did for spying in the 12 mile territorial zone. Moreover, a general principle of international law is that whatever is not explicitly prohibited is permitted (see S.S. Lotus (1927)). Had the Chinese gone ahead with their threats and by their acts caused loss or damage to life and property, it would have been their action that would have been contrary to international law and the Chinese would have been guilty of impeding maritime freedoms.


[1] Military Sealift Command's Special Mission Program controls 24 ships that provide operating platforms and services for unique US military and federal government missions. Oceanographic and hydrographic surveys, underwater surveillance, missile flight data collection and tracking, acoustic research and submarine support are just a few of the specialized services this program supports.