Military Wiki
Clearance Diving Branch
Clearance Diving Branch.jpg
Clearance Diving Branch Badge
Active 1951–Present
Country Australia
Branch Royal Australian Navy
Type Explosive ordnance disposal, reconnaissance
Motto(s) United and Undaunted
Engagements Vietnam War
Gulf War
East Timor
Iraq War

The Clearance Diving Branch is the special forces unit of the Royal Australian Navy (RAN). The Clearance Diving Branch is responsible for combat diving, clearance diving, maritime counter-terrorism and underwater repairs. The Branch consists of two Clearance Diving Teams (CDT).


Clearance divers during a ship boarding exercise in 2006

The RAN has used divers on a regular basis since the 1920s, but it was not until World War II that clearance diving operations came to the fore, with RAN divers working alongside Royal Navy divers to remove naval mines from British waters, and from the waters of captured ports on the European mainland.[1] RAN divers were also used in performing duties including reconnaissance of amphibious landing sites.[1] The skills learned in the European theatre were brought back to Australia, and utilised in the war against Japan.[1] After the war, RAN divers were used during the cleanup of Australian and Papua New Guinea waters of defensive mines.[1]

The utility of clearance and commando divers demonstrated during and after World War II prompted the Australian Commonwealth Naval Board to establish a clearance diving branch within the RAN in 1951.[2][3] Divers were initially attached to the Underwater Research and Development Unit, based at HMAS Rushcutter.[4] In 1956, they were organised into a separate Mobile Clearance Diving Team.[2][4] In March 1966, the divers underwent further reorganisation, splitting into two Clearance Diving Teams.[4] Clearance Diving Team 1 (initially CDT 1, later styled as AUSCDT 1) was the operational team assigned to mine clearance and reconnaissance operations throughout the Australia Station, while Clearance Diving Team 2 (CDT 2/AUSCDT 2) was dedicated to mine warfare in the Sydney area, but was not cleared for operations[verification needed] outside this area.[5]

In late 1966, Clearance Diving Team 3 was established specifically for deployment to the Vietnam War to assist the overworked United States Navy Explosive Ordnance Disposal units, and to give RAN personnel in clearance diving work in an operational environment.[6] Sending CDT 1 or CDT 2, in full or in part, would have impacted on the teams' existing commitments, along with the continuity of training and postings.[7] CDT 3 was formed from available personnel; this was sufficient to keep a six-man team on station in Vietnam from early 1967 until early 1971, with six-month deployments.[8] CDT 3 was disbanded at the end of the Vietnam War, but the designation is reactivated for overseas wartime deployments, including in 1991 for the Gulf War, and again in 2003 for the Iraq War.[9]


Inspecting clandestine naval mines in the Persian Gulf, 2003.

The Clearance Diving Branch consists of units:-

  • Clearance Diving Team One; assigned to the east of Australia and based at HMAS Waterhen in New South Wales
  • Clearance Diving Team Four; assigned to the west of Australia and based at HMAS Stirling in Western Australia

A third unit, Clearance Diving Team Three (AUSCDT THREE) is formed when clearance divers are sent into combat. CDT 3 saw extensive service in the Vietnam War, and during the 1991 Gulf War and the 2003 Iraq War.

There are eight Reserve Diving Teams (RDT) which provide supplementary or surge capability in support of regular CDTs in addition to localised fleet underwater taskings:

  • Reserve Diving Team Five – New South Wales
  • Reserve Diving Team Six – Victoria
  • Reserve Diving Team Seven – Western Australia
  • Reserve Diving Team Eight – Southern Queensland
  • Reserve Diving Team Nine – South Australia
  • Reserve Diving Team Ten – Tasmania
  • Reserve Diving Team Eleven – Northern Territory
  • Reserve Diving Team Twelve – Northern Queensland


Clearance divers speed out to their dive site on a fast insertion boat

A member of Australian Clearance Diving Team One carries his oxygen closed circuit rebreather

The Clearance Divers' roles include:

1. Mine Counter Measures (MCM) and Explosive Ordnance Disposal (EOD):

  • Location and disposal of sea mines in shallow waters
  • Rendering safe and recovering enemy mines
  • The search for and disposal of ordnance below the high water mark
  • Clearance of surface ordnance in port or on naval facilities
  • Search for, rendering safe or disposal of all ordnance in RAN ships and facilities
  • Improvised explosive device disposal (officers and senior sailors)

2. Maritime Tactical Operations:

  • Clandestine beach reconnaissance (including back of beach operations up to 2 km inland)
  • Clandestine hydrographic survey of seabed prior to an amphibious assault
  • Clandestine clearance or demolition of sea mines and/or obstacles
  • Clandestine placing of demolitions charges for the purpose of diversion or demonstration (ship/wharf attacks)
  • Clandestine document collection

3. Underwater Battle Damage Repair:

  • Surface supplied breathing apparatus diving
  • Use of underwater tools including welders, explosive nailguns and pneumatic drills and chainsaws

4. Tactical Assault Group (East):

  • Maritime counter terrorism

5. Counter Piracy:

  • High level boarding operations (TAG qualified divers)


The RAN's diver training program is centred on a 10-day clearance diver acceptance test (CDAT), colloquially known as "hell week". Recruits begin each day at 02:00, and are put through over thirty staged dives designed to test their strength and endurance.[10]

Upon passing selection recruits must successfully pass a number of specialist course to become fully qualified. The Basic Clearance Diver Course spans 37 weeks whilst the Advanced Clearance Diver Course and the Clearance Diving component of the Mine warfare and Clearance Diving Officers course spans 41 weeks. The demands placed on potential applicants to this category are not seen elsewhere in the ADF except with the Special Forces.[11]


Australian personnel unloading supplies from a US Navy helicopter at the port of Umm Qasr, 27 March 2003.

  • In the Vietnam War, Clearance Diving Team 3 was awarded the United States Presidential Unit Citation the United States Navy Unit Commendation twice and the United States Meritorious Unit Commendation for its mine clearance work: see Non-U.S. recipients of U.S. gallantry awards.
  • Took part in Operation Navy Help
  • 1991: Performed mine clearance operations for coalition forces during the Gulf War.
  • 1999: In the East Timor independence crisis as part of INTERFET, CDTs clandestinely mapped harbours and beaches in preparation for the arrival of peacekeepers.
  • 2003: In Operation Falconer (the invasion phase of the Iraq War), CDTs were attached to Commander Task Unit 55.4.3, along with US and British partners, tasked with conducting deep/shallow water mine counter measure operations to clearing shipping lanes. CDTs notably participated in opening up the port at Umm Qasr.
  • 2003–2009: In Operation Catalyst (post-invasion Iraq), CDTs were attached to Coalition counter improvise explosive device (IED) task forces.
  • 2008 – Present: In Operation Slipper – CDTs deployed explosive ordnance disposal (EOD) technicians in Afghanistan and provided tactical boarding parties for ships combating smugglers and piracy.


  1. 1.0 1.1 1.2 1.3 Grey, Up Top, p. 280
  2. 2.0 2.1 Perryman & Mitchell, in Oldham (ed.) 100 Years of the Royal Australian Navy, p. 73
  3. Grey, Up Top, pp. 280–1
  4. 4.0 4.1 4.2 Grey, Up Top, p. 281
  5. Grey, Up Top, pp. 281–2
  6. Grey, Up Top, p. 282
  7. Grey, Up Top, pp. 282–3
  8. Grey, Up Top, pp. 282–3, 290–1, 318–9
  9. Perryman & Mitchell, in Oldham (ed.) 100 Years of the Royal Australian Navy, p. 74
  10. "Hell Week". 
  11. "Clearance Diving Team One". Organisation: Clearance Diving Teams. Royal Australian Navy. Retrieved 30 July 2015. 


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