Apo Reef of the nearest coast of the Philippine island of Mindoro. It is separated from main island by the Apo East Pass of the Mindoro Strait. Politically, the reef lies within the jurisdiction of the Province of Occidental Mindoro in Region IV-B of the Philippines and more accurately of the Municipality of Sablayan. Tourism activities are administered by local government of Sablayan and the local office of the Department of Environment and Natural Resources (DENR). Apo Reef is roughly a triangular coral atoll formation approximately from the north to the south tip, and from east to west. It is separated by
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