As harbours go, Hobart's is about as good as it gets sheltered, deep and able to take a fleet of ships with room to spare.

At the end of Castray Esplanade is the site of Hobart's first signalling station part of a system of stations used to communicate with ships and to signal that a vessel was approaching. Signalling as done with flags from 1818 until 1829, when Governor George Arthur introduced a system of large moving arms the tall structure at the front of the cottage.

Antarctic ships - explorers, whalers, sealers heading to and from the Antarctic made use of the semaphore system. It was still in use in the 1890s, and as late as the 1920s flags were still being used to indicate the identity of an incoming ship.

Just across the road is the CSIRO's Marine Research Division, which as Australia's oceans research centre is a major participant in Australia's Antarctic program. Its fisheries research vessel Southern Surveyor frequently works in the Southern Ocean.