LRSS Squadron has its roots in 45 Port Maintenance Squadron, raised as a Supplementary Reserve Unit on June 26 1955 from the staff of the Maritime Services Board. Its role was to investigate, survey, design and supervise Engineer tasks in support of Port and Logistics over the Shore (LOTS) in the Area of Operations (AO). In 1961, the Unit was reorganised and became part of 5,6,7 and 8 Port Construction and Repair Teams. In 1963, the teams moved to Chowder Bay and became part of 11 Port Regiment, later 1 Terminal Group.
1 Port Construction and Repair Gp (1 PC & R Gp) with the Port Construction teams was formed in 1971. In September 1994 a decision by Land Headquarters saw 1 Port Construction and Repair Group disbanded. The HQ element formed part of the new Combat Engineer Regiments (CER) and the hydrographic and land survey component formed a reserve element for 19 CE Works at Randwick. 19 CE Works consisted of 39 personnel and with the addition of 43 from 1 PC and R Gp, this consolidation gave 19 CE Works more resources and a hydrographic capability.
LRSS Squadron was attached to 21 Const Regt in 2007 and continues to provide an important hydrographic survey capability for Army. Many of the Squadron members are also employees of Sydney Ports, thereby retaining a long standing tradition with its predecessor, the Maritime Services Board.
The unit symbol, the Black Swan, was instituted by the Officer Commanding of 1 PC & R Gp. A medal was struck from a can of Swan Lager and awarded to a Corporal. This award was for his performance (or lack thereof) at the AFX, SME Moorebank 1980.