Motor Launch
R.J. Searles, Birkenhead South Australia
22 September 1942
6 July 1944
Dimensions & Displacement
Length 40 feet 6 inches
Beam 10 feet 6 inches
Draught 5 feet 6 inches
Speed 8 knots
Guns 1 x .303 inch Vickers machine gun
Other Armament 2 x 5lb depth charge

With much of the Royal Australian Navy fleet deployed to foreign waters in the early years of World War II, the defence of Australia’s coastlines became a primary concern for the Naval Board. The Naval Auxiliary Patrol (NAP) was a war-raised unit approved on 25 June 1941, charged with patrolling and safeguarding Australia's inner harbours, ports, rivers and estuaries against enemy sabotage or attack. The NAP fleet was comprised primarily of former pleasure craft, offered freely by their owners.

In May 1942, the NAP was transferred to the Royal Australian Naval Volunteer Reserve (RANVR) and was thereafter known as the RANVR NAP. By October 1942 the total strength of the NAP had increased to over 3000 mobilised and unmobilised reserves. This was to remain the case until early 1944 when it was considered that the danger of enemy attack was remote enough to reduce the strength of the NAP to a minimum.

Originally named Beth, Sundowner was a 40 foot Motor Launch that served as a Naval Auxiliary Patrol Vessel. The boat was requisitioned for naval service on 23 August 1942 before being commissioned into the RAN on 22 September 1942 under the command of Naval Auxiliary Patrol Skipper Reginald H Webb. HMAS Sundowner was decommissioned and returned to her owners on 31 July 1944.

HMAS Sundowner first appeared in the October 1943 edition of the Navy List:
HMAS Sundowner first appeared in the October 1943 edition of the Navy List: