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
Coral Sea Marine Park encompasses the former Coral Sea Conservation Zone, former Coringa-Herald National Nature Reserve and former Lihou Reef National Nature Reserve. The Coral Sea Marine Park has been assigned IUCN protected area category IV. However, within the marine park there are multiple protection zones, each zone has an IUCN category and related rules for managing activities to ensure the protection of marine habitats and species. The following table is a summary of the zoning rules within the Coral Sea Marine Park: Coral Sea Marine Park The Coral Sea Marine Park (previously known as the Coral Sea Commonwealth Marine Reserve) is an Australian