The Andaman Sea is a body of water that is part of the Indian Ocean. It is located to the east of the Andaman Islands that belong to India, from which it takes its name, and to the north of Sumatra, the north-west of the Malay Peninsula, to the west of Thailand, to the south of Myanmar, and to the south-east of the Bay of Bengal. There are many islands and islets in the Andaman Sea, including the Nicobar Islands, and of the Thailand coast, the most significant are Phuket, the Phi Phi Islands, Ko Tapu and the islands of the Krabi Province.

The coastal regions of the Andaman Sea are known for their mangrove forests and seagrass meadows. The western coast of the Malay Peninsula is rich with coral reefs, although it is estimated that only 6% is in an ideal condition, despite this there are also several marine national parks, 16 of which off the Thailand coast and four are candidates for inclusion as UNESCO World Heritage Sites. The Andaman Sea’s waters are home to a large variety of fauna, including vulnerable species like the Dugong, the Irrawaddy Dolphin and several sea turtles.

This Sea has an average depth of about 1,000 meters, but is shallower to the north and east due to the silt deposits of the Irrawaddy River, the major river that flows into the sea from Myanmar. Running along the seabed of the Andaman Sea in a roughly north to south direction is the boundary between two tectonic plates, the Burma Plate and the Sunda Plate, which results in a high level of seismic activity and the shifting of these two plates was the cause of the December 2004 earthquake and tsunami that caused significant loss of life.

The 2004 earthquake and tsunami significantly damaged the infrastructure of the fishery industry that has traditionally operated in the Andaman Sea between the coastal countries. Competition for fish in these waters has often been fierce and resulted in conflicts in the past.