The Bohai Sea is a marginal sea approximately 77,000 km2 in area on the east coast of Mainland China. It is the northwestern and innermost extension of the Yellow Sea, to which it connects to the east via the Bohai Strait.
A medium-sized gulf, the Bohai Sea is enclosed by three provinces and one direct-administered municipality from three different regions of China — Liaoning Province, Hebei Province and Tianjin Municipality, and Shandong Province. The whole of the Bohai Sea is considered a part of both the internal waters of the People's Republic of China and the center of the Bohai Economic Rim. Its proximity to the Chinese capital of Beijing and the municipality of Tianjin makes it one of the busiest seaways in the world.
Wikipedia https://en.wikipedia.org/wiki/Bohai_Sea
Coordinates 38°23'59.64" N 121°0'0.72" E