Natuna Sea
The Natuna Sea () is an extensive shallow sea located around the Natuna Regency, extended from south of the Riau Islands, east of the Lingga Regency and west of Borneo, to the Bangka Belitung Islands. The islands of the Badas and Tambelan Archipelago are located at its center. Mostly located within Indonesian territorial waters, this sea is the southernmost portion of the South China Sea, and geologically is the part of Sunda Shelf. It communicates with the Java Sea to its southeast via the Karimata and Gaspar Strait east and west of Belitung, and with the Strait of Malacca  to the west via the Berhala and Singapore Strait. The International Hydrographic Organization (IHO), in its "Limits of Oceans and Seas", 3rd edition (1953), does not list a Natuna Sea. Instead, the area encompassed by the Natuna Sea is considered the southern portion of the South China Sea. The 1986 draft of the IHO's "Limits of Oceans and Seas" proposed the Natuna Sea, which extends south from the Natuna and Anambas Islands to the Belitung Islands. However, the 1986 draft edition was never approved. Extent. The chains of Anambas and Natuna Islands created arch that connects southeastern tip of  Malay peninsula to western tip of Borneo. This creates the northern boundary of Natuna Sea. While on the south, the southeast coast of Sumatra, the Lingga Islands, Bangka and Belitung islands creates its southern boundary and its opening to Karimata Strait and Java Sea. Geography. Just like South China Sea, Natuna Sea is a marginal part of Pacific Ocean. Natuna sea contains numbers of archipelagos, including: All of these archipelagos are administrated within Riau Islands province. North Natuna Sea. In July 2017, Indonesia renamed the northern reaches of its exclusive economic zone in the South China Sea as the "North  Natuna Sea", which is located north of the Indonesian Natuna Regency, bordering southern Vietnam's exclusive economic zone. The North Natuna Sea is located between the Natuna Islands and Cape Cà Mau on the southern tip of the Mekong Delta in Vietnam.