ABSTRACT
The Gulf of Tongking involves the maritime boundary between China and Vietnam. The gulf is bounded by Vietnam to the west, the mainland of China to the north and Hainan Island to the east. On 26 June 1887, the maritime boundary between China and Indo-China was apparently consigned at the Sino-French Convention. In April 1973, North Vietnam signed an agreement with Ente Nationale Idrocarburi (ENI) for oil prospecting in the gulf. The outer edge of the ENI-proposed Exploration Zone coincided with the median-line boundary between North Vietnam and China. Stalemate continued until 13 December 1979, when Vietnam protested about alleged contracts signed by China for petroleum exploration in the gulf. The key remains the Sino-French Convention of 1887 in which the relevant section reads: The islands which are east of the Paris meridian of 105 43E, that is to say that the northsouth line, passing through the eastern part of Tahas Kau or Quan Chou is also allocated to China.
