 Lagoonal reefs are found in the southern Great Barrier Reef, and further north, off the coast of Princess Charlotte Bay.Crescentic reefs are the most common shape of reef in the middle of the system, for example the reefs surrounding Lizard Island.Crescentic reefs are also found in the far north of the Great Barrier Reef Marine Park, and in the Swain Reefs (20–22 degrees south).