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The Signal Station, Bluff, New Zealand
Though the postcard caption does not say so, the signal station at Bluff probably qualified as the southern most signal station at the time this card was published around 1910.
Signal stations monitored flag signals from vessels at sea and relayed them to shore-based locations. For example, an approaching ship's imminent arrival at Bluff might be signaled from the ship including information about whether a doctor was required upon docking, the ship was carrying mail, the ship required assistance, and so on. Signals might also be sent in either direction about weather conditions such as approaching storms. Flag signals were soon to be superceded by wireless radio when this picture was taken.
The Awarua wireless radio station at Invercargill did not open until 1913. Its task was to monitor marine radio for distress signals and other communication in the southern oceans. On the night of 23 March 1916 it was Alfred Goodwin at Awarua who picked up a distress signal from Ernest Shackleton's Ross Sea party that their ship the Aurora had been disabled by sea ice and they needed assistance.