Apo Reef two lagoon systems, the north and south lagoons which are bounded by narrow reef platforms. It is a almost triangular northern and southern atoll-like reefs separated by a deep channel that is open to the west. The channel runs east to west from deep with a fine white sand bottom, numerous mounds and patches of branching corals under the deep blue water. The north lagoon is an enclosed triangular coral reef platform partly exposed during low tide. It is relatively shallow with depths of about . While the south lagoon is an inverted triangular coral platform enclosed on two sides
Zhongzhou Reef Zhongzhou Reef Zhongzhou Reef also known as Ban Than Reef and Centre Cay (; ) is a small coral reef on the north edge of the Tizard Bank in the Spratly Islands, South China Sea. It lies east of ROC-occupied Taiping Island (Itu Aba), west of Vietnamese-occupied Sand Cay, and has an exposed area of approximately during high tide, and during low tide. It consists of an accumulation of seashells, sand, coral reefs and debris which forms a circular coral reef plate, surrounding the reef under the water, with a diameter of approximately . The reef is currently controlled by