Two major gulfs in the East Sea are the Gulf of Tonkin and the Gulf of Thailand. They are of special importance to the related countries, including: Vietnam, China, Thailand, Malaysia and Cambodia.
Located in the Northwestern portion of the East Sea between Vietnam and China, the Gulf of Tonkin is one of the largest saltwater gulfs in the world, covering an area of about 126,250 square km, with its widest place of about 310 km, and narrowest place of about 207 km. The gulf has two estuaries, the Quynh Chau Strait which is 35.2 km wide and located between Lei Chau Peninsula and Hainan Island of China, and the main gate is defined as a straight line from Con Co Island, Quang Tri Province of Vietnam to Oanh Ca Cape, Hainan, China which is about 207 km wide. The Gulf of Tonkin’s coast stretches 10 provinces and cities of Vietnam with a total length of roughly 763 km and two provinces of China with a total length of about 695 km. The Gulf of Tonkin is relatively shallow (less than 60 m in depth). The Red River is the main river flowing into this bay. Some major ports in the Gulf include: Hai Phong, Vinh in Vietnam and Bac Hai of China. The part of the Gulf that is under the control of Vietnam has about 2,300 islands, coastal rocks, such as Bach Long Vi, Cat Ba, Co To, etc. The Chinese side has Hainan Island and a few small islands in the northeast of the Gulf, such as Vi Chau, Ta Duong, etc.
The Gulf of Tonkin contains many resources. There are many large fishing grounds in the Gulf, providing an important source of seafood for people of the two countries. Forecasts show that its bed and underground have potential for oil and gas. The gulf has long become the gateway of Vietnam to the world. It is of special importance to the country’s cause of economic development, international trade as well as national defence and security. At the same time, the gulf holds an important strategic position to Vietnam and China both in terms of economy, defense and security. The two countries signed the Agreement on Boundary Delimitation in the Tonkin Gulf on December 25, 2000.
The Gulf of Thailand, also known as the Gulf of Siam, is a semi-enclosed sea, with an area of about 320,000 km2, limited by the coasts of the four countries of Thailand (1,560 km), Vietnam (230 km), Malaysia (150 km) and Cambodia (460 km). The border of the Gulf is determined by the road connecting the Ca Mau Cape of Vietnam to the Malaysian city of Kota Baru. The length of the bay is about 830 km, while its average width is 385 km.
The Gulf of Thailand is relatively shallow. Its average depth is only about 45 m. The deepest place is 80 m. The main rivers that flow into this Gulf include: Chao Phraya and Mae Klong of Thailand. The strong currents of water from these rivers make the Gulf waters relatively pale and rich in sediments. Due to the relatively high temperature of the tropics, there are many coral reefs in the waters of the gulf, such as: Ko Samui, Ko Tao in Thailand, and Phu Quoc of Vietnam. These are favorable conditions to develop tourism to serve tourists with diving interests. In addition, the Gulf also has a relatively large reserve of oil and gas.
According to the 1982 United Nations Convention on the Law of the Sea, the entire Gulf of Thailand is subject to extended jurisdictional claims, leading to contradictions over territorial division between countries of Thailand, Vietnam, Malaysia and Cambodia. For Vietnam and Thailand, after 9 rounds of negotiation, on August 9, 1997, the two countries signed an Agreement on delimitation of maritime boundaries between the two countries in the Gulf of Thailand. This is the first maritime delimitation agreement reached in this region. Currently, there are still problems in delimiting the sea between Vietnam - Cambodia, Thailand - Cambodia, Vietnam - Thailand - Malaysia, Vietnam - Cambodia - Thailand.
PHAM BINH