Southern boobook their upperparts. The tips of their feathers are white and fluffy, remnants of the nestlings' down. These are worn away over time, persisting longest on the head. The feathers of the head, neck and underparts are fluffier overall. Immatures in their second and third year have plumage more like adults, though their crowns are paler and more heavily streaked. On mainland Australia, it could be confused with the barking owl or the brown hawk-owl ("Ninox scutulata"), a rare vagrant to the northwest, although the southern boobook is easily distinguished by its squat posture and distinctive pale border to its face
Australasian Hydrographic Society and gas industries, particularly off the north west coast of Western Australia and coal export facilities in Queensland have required a considerable increase in the provision of accurate and up to date hydrographic information. The attendant increase in trade, for example, has made improved navigation through sensitive area, such as the Great Barrier Reef critical. Hydrography also plays an important role in national security, border protection and humanitarian support. The Australasian Hydrographic Society endeavours to represent all interests in these domains. The Australasian Hydrographic Society consequently "aims to serve anyone with an interest in the science (and art)" of hydrography,