The 20th Minesweeping Flotilla was a Royal Australian Navy

Royal Australian Navy

The Royal Australian Navy is the naval branch of the Australian Defence Force. Following the Federation of Australia in 1901, the ships and resources of the separate colonial navies were integrated into a national force: the Commonwealth Naval Forces...

 minesweeping flotilla

Flotilla

A flotilla , or naval flotilla, is a formation of small warships that may be part of a larger fleet. A flotilla is usually composed of a homogeneous group of the same class of warship, such as frigates, destroyers, torpedo boats, submarines, gunboats, or minesweepers...

 that operated during World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

. Formed on 9 December 1939 and styled in the naming convention for minesweeping flotilla names used by the Royal Navy, the flotilla consisted of HMAS Swan

HMAS Swan (U74)

HMAS Swan , named for the Swan River, was a Grimsby class sloop of the Royal Australian Navy that served during World War II.-Design and construction:...

, Yarra

HMAS Yarra (U77)

HMAS Yarra , named for the Yarra River, was a Grimsby class sloop of the Royal Australian Navy that served during World War II. Commissioned in 1936, Yarra spent the early part of the war in Australian waters, then was transferred to the East Indies Station in 1940...

, Doomba

HMAS Doomba

HMAS Doomba was a Royal Australian Navy warship of World War II. Built for the Royal Navy around the end of World War I as the Hunt-class minesweeper HMS Wexford, the ship only saw two years of service before she was decommissioned in 1921 and sold to the Doomba Shipping Company...

 and Orara. The makeup of the flotilla changed during the course of the war.

Ships of the flotilla

• HMAS Swan
  HMAS Swan (U74)
  HMAS Swan , named for the Swan River, was a Grimsby class sloop of the Royal Australian Navy that served during World War II.-Design and construction:...
  
  
• HMAS Yarra
  HMAS Yarra (U77)
  HMAS Yarra , named for the Yarra River, was a Grimsby class sloop of the Royal Australian Navy that served during World War II. Commissioned in 1936, Yarra spent the early part of the war in Australian waters, then was transferred to the East Indies Station in 1940...
  
  
• HMAS Doomba
  HMAS Doomba
  HMAS Doomba was a Royal Australian Navy warship of World War II. Built for the Royal Navy around the end of World War I as the Hunt-class minesweeper HMS Wexford, the ship only saw two years of service before she was decommissioned in 1921 and sold to the Doomba Shipping Company...
  
  
• HMAS Orara
• HMAS Warrego
  HMAS Warrego (U73)
  HMAS Warrego , named for the Warrego River, was a Grimsby class sloop of the Royal Australian Navy .-Construction:She was laid down by the Cockatoo Island Dockyard at Sydney on 10 May 1939, launched on 10 February 1940, and commissioned into the RAN on 21 August 1940.-Operational history:Warrego...
  
  
• HMAS Warrnambool
• HMAS Echuca
  HMAS Echuca
  HMAS Echuca , named for the town of Echuca, Victoria, was one of 60 Bathurst class corvettes constructed during World War II, and one of 36 initially manned and commissioned solely by the Royal Australian Navy .-Construction:...
  
  
• HMAS Burnie
  HMAS Burnie
  HMAS Burnie , named for the port city of Burnie, Tasmania, was one of 60 Bathurst class corvettes constructed during World War II and one of 20 built for the Admiralty but manned by personnel of and commissioned into the Royal Australian Navy .Entering RAN service in April 1941, Burnie saw action...