The Largs Bay jetty was built by private enterprise in 1882 as part of a plan to attract the large overseas mail steamers to use the facilities. Despite the continual dredging at Port Adelaide the size of these vessels continued to exceed the capacity of the port, and the project at Largs Bay would essentially provide a deep water anchorage, until finally in 1908 the Outer Harbor at the entrance to the Port River was opened.

The jetty was 640 metres long and its width varied: 7.3 metres for the first 564 metres widening to 15 metres for the final 76 metres to the 'L-head'. The extra width at the end of the jetty was to enable the shunting of the trains. There was a 19 feet depth at the outer end at low tide.

The mail steamers operated by P & O and Orient Lines used the Largs Bay anchorage from 1888-1908 when Outer Harbor opened. As they did not berth at the jetty, mail and passengers were carried out to the ships in a variety of government and privately operated steam launches which moored at the landing alongside the Defiance.