Semaphore: 50 Years of Exercise RIMPAC

October 2021 marks 50 years since the navies of Australia, Canada, New Zealand, and the United States took part in the first Exercise Rim of the Pacific (RIMPAC). The biennial, US-led exercise is held in Hawaii and in the waters off Southern California. Military forces from nations circling the Pacific Rim and beyond are invited to participate in training and war game exercises. The vast array of activities completed during an exercise include gunnery and missile firings, anti-submarine and air defence exercises, mine clearance operations, and amphibious landings. For all participants, RIMPAC offers an opportunity to strengthen maritime partnerships, enhance interoperability, and sharpen capabilities across a range of environments. In its 50 year history, 28 countries have participated in 27 RIMPAC exercises. Australia joins the US and Canada as one of only three nations to have participated in every exercise.

The first RIMPAC exercises received relatively little media attention, quietly taking place with little fanfare. By the mid-1980s, however, as the span of operations continued to increase and the number of participating personnel often reached 50,000, the exercise regularly received multi-page spreads in Navy News. Today, RIMPAC is the world’s largest maritime warfare exercise and is, arguably, the most highly sought after deployment among Royal Australian Navy (RAN) personnel.

HMAS Yarra (III) departing Pearl Harbor to participate in the first RIMPAC. Note the lei worn around the ship’s bow, emulating the traditional dress of the Indigenous Hawaiian peoples.

RIMPAC 84 makes front page news.

Early RIMPAC exercises reflected the Cold War context in which they were conceived, with a clear enemy in mind and consistent exercise structure. The participating forces were split into one of two groups, Orange or Blue Force, with Orange units simulating different classes of ships from the Soviet Navy fleet. The two forces would depart Pearl Harbor and proceed to the Pacific Missile Range Facility (PMRF), Barking Sands for gunnery and missile firing and evaluation. This was followed by holding operations in support of a carrier task group conducting strikes and missile firings, concluding with an opposed transit and re-entry into Pearl Harbor.^[1]

The PMRF, which includes more than 40,000 square miles of open ocean range and 1000 square miles of fully instrumented underwater range, is the largest range capable of simultaneously supporting surface, subsurface, air, and space operations. The PMRF offered a valuable opportunity to test the Australian designed and developed Ikara missile system. Following RIMPAC 71 Minister for the Navy, Dr Malcolm Mackay, AM, reported that the:

...most modern US equipment was made available to the RAN to track the missiles in flight and to follow the path of the torpedos under water…[giving] the RAN information on the performance of Ikara which could not have been obtained through Australian test facilities.” The Ikara system “proved itself under realistic tactical conditions” and “the confidence…in the Ikara System…increased tremendously”.^[2]

As RIMPAC became a regular feature on the calendar of naval exercises, it matured and scenarios became more sophisticated. In his reports of proceedings detailing RIMPAC 78, Captain JB Snow, RAN, Commanding Officer of HMAS Supply, described the “imaginative and comprehensive” intelligence summaries that set out a scenario of a cold war deteriorating into a hot war.^[3] These scenarios provided a realistic multi-threat training environment that simply could not be duplicated outside of the RIMPAC context.

The true value of the multinational cooperation and interoperability developed during RIMPAC exercises was apparent during Gulf War I. On 10 August 1990, Australian Prime Minister Bob Hawke announced his government’s decision to dispatch an RAN task group to join the Multinational Naval Force (MNF) then assembling in response to Iraq’s invasion of Kuwait. As part of Operation DAMASK, HMA Ships Success, Adelaide, and Darwin joined the US-led MNF.^[4] Having just returned from RIMPAC 90, the ships were at a high level of readiness and used their “fresh RIMPAC experience” to quickly and effectively integrate into the MNF.^[5] Then Defence Minister Senator the Hon. Robert Ray reflected on the RAN’s success in Gulf War I and the learning developed at RIMPAC:

While the Gulf engagement was outside our region, Australian ships were able to move into effective operations with allied nations - in particular the United States - with great ease. Our ability to operate effectively with the US and other friendly nations depends in large measure on participation in exercises such as RIMPAC.^[6]

Certainly, Gulf War I underscored the important role that RIMPAC plays in ensuring the readiness, responsiveness, and flexibility of participating forces. Coincidently, RIMPAC 1990 was the final Cold War era exercise and Gulf War I ushered in a new heightened focus on the Middle East in the foreign and defence policy of the US and its allies.

As the Cold War ended, strategic thinking and defence commitments by the US and its partners increasingly focused on peacekeeping, proactive military involvement in order to shape the strategic setting, and, ubiquitously, conflict in the Middle East. RIMPAC evolved accordingly. There was a growing emphasis on littoral warfare and activities pertinent to peacekeeping and humanitarian aid and disaster relief (HADR), including boarding operations, simulated mass casualty evacuations, and amphibious landings.^[7] This shift started in 1998, with the first simulated oil spill trial in the history of the exercise. A pipeline rupture poured 20,000 gallons of diesel fuel into Pearl Harbor and RIMPAC participants were assessed on their ability to provide a coordinated response, with the USN noting that in the event of a real spill “Navy teams would act as a first line of defence”.^[8]

HMAS Tobruk (II) conducted an evacuation exercise during RIMPAC 08. News reports noted that “future ADF-hosted exercises and operations are likely to include complex mass casualty and noncombatant evacuation exercises aimed at enhancing Australia’s capability in responding to humanitarian and political crises in our region.”^[9]

Future Chief of Navy, Commander Mike Noonan, RAN, Commanding Officer of HMAS Parramatta, reflected on the changing focus of the exercise following RIMPAC 04. The exercise had an increased focus on boarding operations and while Parramatta was performing her first boarding in company with HMCS Protecteur, personnel had to contend with attacks from ashore by small boats simulating Boghammers - the fast patrol boats popularly used by Iran in the 1984-88 Tanker War, and, more recently, by Somali pirates. This activity, Noonan noted, provided “a realistic threat” and further demonstrated “the shift away from blue water warfare and a move towards littoral warfare”.^[10] It has been this adaptability to changing technologies, capability requirements, and strategic threats that has seen RIMPAC remain so relevant and useful to participants over the last 50 years.

RAN landing craft and US Marine Corps amphibious assault vehicles complete an amphibious operation for RIMPAC 18.

RIMPAC 20: Boarding Party members from FS Bougainville - sporting personal protective equipment - approach HMAS Stuart (III) during an interoperability training exercise.

In more recent years, the acquisition of the Canberra Class LHD and its impressive amphibious capabilities has expanded the range of activities the RAN is able to participate in during RIMPAC exercises. The LHD has a sophisticated air-land-sea deployment system, a capability that was tested at RIMPAC 16 when almost 500 soldiers from four nations, 54 vehicles, and 12 trailers were landed by HMAS Canberra’s landing craft during a 7 hour long evolution. This operation saw US amphibious assault vehicles embarked and landed by Canberra for the first time, marking a significant milestone in for the ship’s company in terms of cooperation with coalition forces. The 2016 exercise also Canberra conduct a number of interoperability trials, including the landing of a US Marine Corps MV-22 Osprey and US Marine Corps CH-53E Super Stallion helicopter - among the largest and heaviest in the world. These high-end trials were not only a testament to the RAN’s ability to work closely and effectively with its foreign partners, but also the LHD’s agility and adaptability to a range of aircraft.^[11]

In August 2020, Australia joined nine other countries for RIMPAC 20, the 27th exercise in the series and, arguably, among the most unique and challenging to date. Held amid the COVID-19 crisis, RIMPAC 20 was a modified at-sea only event that ran for two weeks rather than the initially planned five. There were also strict pre-deployment requirements - including comorbidity checks and a 14-day isolation period - to protect the health and safety of all participating personnel.^[12]

The at-sea only nature of the exercise required special provisions and considerations. Without opportunities to step ashore, Commanding Officers thought creatively about how to provide rest and recreation opportunities. For instance, HMAS Hobart, which was participating in its first RIMPAC, embarked a range of recreation equipment. Commanding Officer Commander Ryan Gaskin, RAN, remarked on the value of these additional comforts on board:

The team remain buoyant and optimistic despite COVID-19 restrictions impeding their liberty and confining them to the ship. Our preparation for this deployment included the provision of a raft of recreational options to keep Ship’s Company entertained and engaged including the Junior Sailors’ Bar, Flight Deck movie screen and projector, golf simulator and inflatable pools. It’s been fascinating to witness them making use of these facilities, enjoying their downtime and finding unique ways of achieving genuine respite.^[13]

The RAN’s often unassuming replenishment capabilities were a particular highpoint during RIMPAC 20. Replenishment ships have, of course, always been a feature of RIMPAC exercises. With RIMPAC 20 an at-sea only event, however, their role in sustaining forces and extending reach at sea was more important than ever.^[14] As one of only two supply ships involved in the 2020 exercise, HMAS Sirius was particularly busy, performing 19 refuellings over the course of the exercise.^[15]

Although RIMPAC 20 saw a lower tempo of activities compared to previous years, RAN personnel were still able to complete a full spectrum of military operations including anti-submarine and anti-drone warfare exercises, a multinational harpoon missile firing (the most complicated firing undertaken by the RAN to date) and multinational Officer of the Watch manoeuvres.^[16] Equally as important as training opportunities was the diplomatic and strategic value of Australia’s presence at RIMPAC during a period of increasing uncertainty on the international stage. As then Defence Minister Senator the Hon. Linda Reynolds, CSC, noted:

It’s important during global challenges that Australia continues to demonstrate its commitment to its partners and to a secure and prosperous region.^[17]

Reynold’s remark speaks to the enduring themes of RIMPAC throughout its 50 year history. For Australia, the value of RIMPAC largely centres on strengthening people-to-people partnerships, interoperability, and demonstrating Australia’s presence and commitment to its region.

1. ↑Reports of Proceedings November 1978, HMAS Melbourne, Australian War Memorial (AWM) 78, 222/17; Reports of Proceedings September 1972, HMAS Brisbane, AWM 78, 70/5.
2. ↑‘Ikara firing success in Hawaii exercise’, Navy News, 10 December 1971, 1.
3. ↑Reports of Proceedings April 1978, HMAS Supply, AWM 78, 327/12.
4. ↑David Stevens and John Perryman, ‘Gulf War I - Operation DAMASK’, https://www.navy.gov.au/history/feature-histories/gulf-war-i-operation-damask.
5. ↑The RIMPAC Experience, Maritime Command Australia, Directorate of the Public Information - Navy, Sea Power Centre - Australia Collection (SPC-A).
6. ↑‘Five RAN Units in Pacific Exercise’, Navy News, 19 June 1992, 3.
7. ↑‘RIMPAC Sails into the Sunset’, 24 August 1998, Navy News, 9; ‘Exercise a Pearler for Aussie Units’, Navy News, 29 July 2004, 19.
8. ↑‘RIMPAC Sails into the Sunset’, 24 August 1998, Navy News, 9.
9. ↑‘RIMPAC Sailors Provide Casualties to Medical Mass Casualty Exercise’, 15 August 2008, Navy News, 2.
10. ↑Reports of Proceedings July 2004, HMAS Parramatta, July 2004, SPC-A.
11. ↑‘Big Birds on Deck’, 28 July 2016, Navy News, 12; Reports of Proceedings July 2016, HMAS Canberra, SPC-A.
12. ↑Regional Presence Deployment and RIMPAC Medical Quick Reference Guide.
13. ↑Reports of Proceedings June 2020, HMAS Hobart, SPC-A.
14. ↑‘Sirius shows off RAS skills’, 17 September 2020, Navy News, 11.
15. ↑Reports of Proceedings August 2020, HMAS Sirius, SPC-A.
16. ↑‘Navy excels during live missile firing’, Defence News, 31 August 2020, https://news.defence.gov.au/capability/navy-excels-during-live-missile-firing.
17. ↑‘Ships deploy to Southeast Asia and Exercise Rim of the Pacific in Hawaii’, 5 July 2020, Media Statement, Minister for Defence, https://www.minister.defence.gov.au/minister/lreynolds/media-releases/ships-deploy-southeast-asia-and-exercise-rim-pacific-hawaii.