Andaman Sea in the context of "Gulf of Martaban"

The Indian Ocean is the third-largest of the world's five oceanic divisions, covering 70,560,000 km (27,240,000 sq mi) or approximately 20% of the water area of Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by the Southern Ocean or Antarctica, depending on the definition in use. The Indian Ocean has large marginal or regional seas, including the Andaman Sea, the Arabian Sea, the Bay of Bengal, and the Laccadive Sea.

Geologically, the Indian Ocean is the youngest of the oceans (being directly preceded by the Tethys Ocean, which fragmented into the Mediterranean Sea and the Indian Ocean only 20 million years ago), and it has distinct features such as narrow continental shelves. Its average depth is 3,741 m. It is the warmest ocean, with a significant impact on global climate due to its interaction with the atmosphere. Its waters are affected by the Indian Ocean Walker circulation, resulting in unique oceanic currents and upwelling patterns. The Indian Ocean is ecologically diverse, with important ecosystems such as coral reefs, mangroves, and sea grass beds. It hosts a significant portion of the world's tuna catch and is home to endangered marine species. The climate around the Indian Ocean is characterized by monsoons.

The Mergui Archipelago (also Myeik Archipelago or Myeik Kyunzu; Burmese: မြိတ်ကျွန်းစု) is located in far southern Myanmar (Burma) and is part of the Tanintharyi Region. It consists of around 800 islands, varying in size from very small to hundreds of square kilometres, all lying in the Andaman Sea off the western shore of the Malay Peninsula near its landward (northern) end where it joins the rest of Indochina. They are occasionally referred to as the Pashu Islands because the Malay inhabitants are locally called Pashu.

The Strait of Malacca is a narrow stretch of water, 900 kilometres (560 mi) long and from 65 to 250 km (40 to 155 mi) wide, between the Malay Peninsula to the northeast and the Indonesian island of Sumatra to the southwest, connecting the Andaman Sea (Indian Ocean) and the South China Sea (Pacific Ocean). As the main shipping channel between the Indian and Pacific oceans, it is one of the most important shipping lanes in the world.

Thailand, officially the Kingdom of Thailand, and formerly known as Siam until 1939, is a country located in mainland Southeast Asia. It shares land borders with Myanmar to the west and northwest, Laos to the east and northeast, Cambodia to the southeast, and Malaysia to the south. Its maritime boundaries include the Gulf of Thailand and the Andaman Sea, as well as maritime borders with Vietnam, Indonesia, and India. Thailand has a population of nearly 66 million people, covers an area of approximately 513,115 km (198,115 sq mi). The country's capital and largest city is Bangkok.

Archaeological evidence indicates that humans have inhabited the area of present-day Thailand for at least 40,000 years. Indigenous ethnic groups include the Mon, Khmer, and Malay people. The Tai people are believed to have originated from the Điện Biên Phủ region since the 5th century and began migrating into the territory of modern Thailand between the 8th and 10th centuries origin of the Tai people. During the classical historical period, major kingdoms such as Sukhothai, Lan Na, and Ayutthaya were established. The Sukhothai Kingdom is regarded as the beginning of Thai history, while the Ayutthaya Kingdom, founded in 1350 CE, became a regional power replacing the Khmer Empire. European contact began in 1511 CE when Portuguese envoys arrived in Ayutthaya. The Ayutthaya Kingdom flourished until its complete destruction during the 1765–1767 Burmese–Siamese War by the Burmese forces under the Konbaung dynasty in 1767.

Myanmar, officially the Republic of the Union of Myanmar and also referred to as Burma (the official English name until 1989), is a country in northwest Southeast Asia. It is the largest country by area in Mainland Southeast Asia and has a population of about 55 million. It is bordered by India and Bangladesh to the northwest, China to the northeast, Laos and Thailand to the east and southeast, and the Andaman Sea and the Bay of Bengal to the south and southwest. The country's capital city is Naypyidaw, while its largest city is Yangon (formerly Rangoon).

Early civilisations in the area included the Tibeto-Burman-speaking Pyu city-states in Upper Myanmar and the Mon kingdoms in Lower Myanmar. In the 9th century, the Bamar people entered the upper Irrawaddy valley, and following the establishment of the Pagan Kingdom in the 1050s, the Burmese language and culture and Theravada Buddhism slowly became dominant in the country. The Pagan Kingdom fell to Mongol invasions, and several warring states emerged. In the 16th century, reunified by the Taungoo dynasty, the country became the largest empire in the history of Southeast Asia for a short period. The early 19th-century Konbaung dynasty ruled over an area that included modern Myanmar and briefly controlled Assam, the Lushai Hills, and Manipur as well. The British East India Company seized control of the administration of Myanmar after three Anglo-Burmese Wars in the 19th century, and the country became a British colony. After a brief Japanese occupation, Myanmar was reconquered by the Allies. On 4 January 1948, Myanmar declared independence under the terms of the Burma Independence Act 1947.

The Andaman and Nicobar Islands is a union territory of India comprising 836 islands, of which only 31 are inhabited. The islands are grouped into two main clusters: the northern Andaman Islands and the southern Nicobar Islands, separated by a 150 km (93 mi) wide channel. The capital and largest city of the territory, Port Blair (officially Sri Vijaya Puram), is located approximately 1,190 km (740 mi) from Chennai and 1,255 km (780 mi) from Kolkata in mainland India. The islands are situated between the Bay of Bengal to the west and the Andaman Sea to the east. The northernmost point is 901 km (560 mi) from the mouth of the Hooghly River. Indira Point, located at 6°45'10″N and 93°49'36″E on the southern tip of Great Nicobar, is the southernmost point of India.

The territory shares maritime borders with Indonesia located about 165 km (103 mi) to the south, Myanmar located 280 km (170 mi) to the north-east and Thailand located 650 km (400 mi) to the south-east. The islands occupy a total land area of approximately 8,249 km (3,185 sq mi) with a population of 380,581 as per the 2011 census. The territory is divided into three districts: Nicobar, South Andaman, and North and Middle Andaman with the capitals at Car Nicobar, Port Blair and Mayabunder respectively.

Tanintharyi Region, formerly Tenasserim Division and Tanintharyi Division, is a region of Myanmar, covering the long narrow southern part of the country on the northern Malay Peninsula, reaching to the Kra Isthmus. It borders the Andaman Sea to the west and the Tenasserim Hills, beyond which lie Thailand, to the east. To the north is the Mon State. There are many islands off the coast, the large Mergui Archipelago in the southern and central coastal areas and the smaller Moscos Islands off the northern shores. The capital of the division is Dawei (Tavoy). Other important cities include Myeik (Mergui) and Kawthaung. The division covers an area of 43,344.9 square kilometres (16,735.6 sq mi), and had a population of 1,406,434 at the 2014 Census.