The back of Reef 18-025 is sheltered from the prevailing wind and sea conditions found within the lagoon of the Great Barrier Reef. Manta tow surveys were conducted on the reef slope. The reef slope is generally steep dropping off into deep water with no discernable bottom. The reef structure has few features including bommies.

The benthic community was dominated by coralline/turf algae, but sand, hard coral, soft coral and gorgonian were also common. Hard coral cover on the reef back was low composed mainly of Porites species. The dominant coral lifeform was massive, but other forms such as branching and foliose corals were also present in decreasing order of abundance. Coral bleaching was present on a few individual colonies.

The fish abundance on the back of Reef 18-025 was very high. Conspicuous groups of reef fishes included parrotfish, surgeonfish, snapper, baitfish and pelagic predators. No crown-of-thorns starfish were observed on the back of Reef 18-025 . White syndromes (such as white band disease or shutdown reaction) were present on hard corals.