Yellow Sea, a shallow arm of the Pacific Ocean between China and Korea. It covers roughly 180,000 square miles (470,000 km2) and reaches a maximum depth of about 300 feet (90 m). Bo Gulf and Korea Bay are major extensions to the north. The Yellow Sea merges with the East China Sea on the south. The Huang He, or Yellow River, brings enormous amounts of yellow silt into the sea—hence the name of the sea. Ports include Lüda and Qingdao in China and Inchon in South Korea.