[http://coastradio.info/adelaide.html]
...
In 1912 a new Navigation Act made it compulsory for every foreign going ship, Australian built ship or ship engaged in coastal trade carrying 50 or more persons, including passengers and crew, trading in Australian waters to be equipped with apparatus for wireless telegraphy.
By 1913 there were some 50 radio equipped ships using Australian call signs.
These included 20 Government vessels and ships operated by the Adelaide Steamship Company...
...
