Java Sea

Lies between Borneo, Java, and Sumatra, open on the north to the South China Sea; area about 433,000 sq km/167,200 sq mi. Lying on the Sunda continental shelf, its average depth is only 46 m/150 ft. Monsoon winds control surface currents, which flow westwards during winter, and reverse in the summer.

Submerged river beds on the Sunda Shelf can be traced back to river mouths on the bordering islands. These form two distinct systems: one which flowed northwards to the South China Sea, and the other which flowed eastwards.