Asia includes the regions of East Asia, South Asia, South East Asia, South West Asia and West Asia. Countries of East Asia are China, Hong Kong (China), Japan, Korea Democratic People's Republic, Korea Republic, Macau and Mongolia. In South East Asia are found Borneo, Brunei Darussalam, Cambodia, Indonesia, Lao, Malaysia, Myanmar, Philippines, Singapore, Thailand, Timor Leste and Viet Nam. In South Asia lie Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan, Sikkim and Sri Lanka. In South West Asia are Afghanistan and the Iran Islamic Republic. In West Asia are Bahrain, Iraq, Israel, Jordan, Kuwait, Lebanon, Oman, Qatar, Saudi Arabia, Syria, United Arab Emirates and Yemen.
The Asian continent is so geographically diverse that one cannot generalize about its oceans and seas. In the north, the Aleutian Islands are a volcanic arc with a trench linking northern Asia to Alaska in the Americas, and through the Bering Sea to the Arctic Ocean. The east coast of Asia lies in the Pacific Ocean, which is the largest and deepest basin containing nearly half of the Earth's free water. Islands are abundant in the north west Pacific; many are volcanoes, some still active. Further west, the Indian sub-continent stretches down into the Indian Ocean. There are low-lying limestone islands with extensive reefs, such as the Maldives. The Red Sea and the Arabian Gulf discharge warm, saline, subsurface water from West Asia into the Indian Ocean. The Mediterranean Sea, a marginal basin, lies between Europe and Africa and has countries of West Asia along its eastern shoreline, ultimately draining into the Atlantic Ocean.

Regional Seas

The South China Sea is a marginal basin formed by an island arc of Indonesia and the Philippines which separates the continent of Southeast Asia from the Pacific Ocean. These islands have the largest number of active volcanoes in the world, with their earthquakes, volcanic activity and resulting tsunamis. Other regional seas in the Pacific include the Sea of Okhotsk, Sea of Japan, Yellow Sea, East China Sea, Sulu Sea, Celebes Sea, Banda Sea, Java Sea, Timor Sea and Arafura Sea. These semi-enclosed waters are sensitive to the heavy loads of industrial wastes, agricultural fertilizers and pesticides as well as areas of increasing population and coastal land use.