About 15km north of Heron Island lies Wilson Island. This tiny island cay is not much larger than 4km in circumference. Unlike One Tree Island, the lagoon at Wilson is permanently submerged and so maintains a continuous connection with surrounding waters; this also maintains the exceptional water clarity. In this lagoon, the shallow reef is absolutely stunning; massive beds of branching and plating corals, as well as the notable Porites bommie which is probably over 500 years old, extending about 4m in height and 5m in diameter. On the other side of the island, the reef concentrates along narrow finger-like projections with shallow sandy channels in between. Although there were some portions of the reef that were completely barren and overgrown with turf algae, other areas were covered in massive colonies of plating coral that were about 1-2m in size. There were also a number of adult Green and Loggerhead Turtles hanging out in this area, as well as one curious Grey Reef Shark with a droopy dorsal fin.