The entire strait is on Asia's continental shelf. It is almost entirely less than deep, with a short ravine of that depth off the south-west coast of Taiwan. As such, there are many islands in the strait. The largest and most important islands off the Fujianese coast are Xiamen, Gulangyu, Pingtan (the "Haitan" of the IHO delineation), Kinmen, and Matsu. The first three are controlled by the PRC; the last two by the ROC. Within the strait lie the Penghu or Pescadores, also controlled by the ROC. There is a major underwater bank north of the Penghu Islands.