Navy’s shipwrecks and the Defence Sovereign Wrecks Agreement
Navy’s shipwrecks are often out of sight and out of mind until they make the news through commemorations or discoveries, and sometimes as the target of salvors or looters. But they are not abandoned, nor are they forgotten, as a new agreement between Defence and the Australian Government department responsible for shipwrecks and other underwater cultural heritage shows.
HMAS AE1 was found in Papua New Guinean waters in December 2017, 103 years after its loss with all hands.
The Australian Government claims ownership of and sovereignty in the wrecks of scores of ships and watercraft and hundreds of aircraft sunk both in Australian and foreign waters. Indeed, Australia claims almost all government-owned vessels or aircraft that have sunk and not been expressly abandoned, and that were operated on a non-commercial basis at the time of sinking.
The periodic discovery of Australian Sovereign vessels and aircraft outside Australian waters has led to bespoke efforts to manage and protect such heritage that are fraught with issues. A more proactive, consistent and enduring approach holds the prospect of more effective and efficient protection and management. This also allows opportunities to build positive strands to bilateral relationships with other countries in whose waters Australian wrecks lie.
Australia’s national authority on all things underwater cultural heritage is the Department of Climate Change, Energy, the Environment and Water (DCCEEW). This department is the sole competent authority in line with Australia’s Underwater Cultural Heritage Act of 2018 (the UCH Act). This Act and Australian government practice align with the UNESCO Convention on the Protection of the Underwater Cultural Heritage (2001).
The UNESCO convention is a global best-practice standard that builds on the United Nations Convention on the Law of the Sea (1982), even though it is not universally accepted. Australia has worked to align state and federal laws with the UNESCO convention and is considering moving towards ratification.
In Australia, each state and the Northern Territory have laws relating to underwater cultural heritage (UCH), but they all address UCH at a state and territory level, while the UCH Act 2018 covers heritage in Australian waters and can even protect Australian UCH outside Australian waters. This is where the Sovereign Wrecks Agreement comes in.
In early 2025, Defence concluded an agreement with DCCEEW regarding the status of Australia’s military wrecks overseas. The agreement, entitled ‘Guidance on how existing policies and legislation apply to Defence underwater cultural heritage sites and clarity on the roles and responsibilities of parties’, is otherwise known as the Sovereign Wrecks Agreement.
The most important guidance is to leave UCH sites undisturbed unless as part of a project formally approved by the appropriate Australian and international authorities. Defence activities discover cultural material that may be UCH on the seabed all the time, but it should be reported and not disturbed.
More than just shipwrecks
This agreement covers all Defence underwater cultural heritage outside Australian waters, which is more than just shipwrecks. The Australian Government claims ownership of and sovereignty in the remains of all vessels and aircraft and their associated articles belonging to or used by the ADF, unless they were captured or surrendered before they sank or have since been expressly abandoned. This also includes vehicles, expended weapons and structures and other artefacts on submerged battlefield sites, like at Gallipoli.
RAAF Baltimore bomber FW282 lost with 3 of its crew in the Aegean Sea in 1943 and discovered in 2024.
The broader definition of UCH includes any trace of human existence that has a cultural, historical or archaeological character that’s located underwater. This includes submerged settlements and structures, artefacts and, importantly for our Defence heritage, any associated human remains. There are some specific exclusions, but basically if it’s made by or associated with humans, is no longer in use and is underwater, it is probably UCH.
The UNESCO convention also has an age caveat in that it has to have been submerged for 100 years, but the Australian UCH Act 2018 does not apply this. It does extend automatic protection to sites submerged for at least 75 years, but not as an element of the definition. This age limit does not apply to the claim of ownership or sovereignty in Defence UCH, which is maintained from the moment it was sunk.
As Defence UCH presents a somewhat special case, constituting the vast majority of Australia’s sovereign owned UCH outside of Australian waters, DCCEEW sought to develop an agreement with Defence on how this should be managed. Basically, this agreement is exactly what it says on the cover; it’s guidance on how the departments will treat Defence UCH sites overseas and who is responsible for what.
Each service is included in the agreement through their lead agency, the Sea Power Centre – Australia for Navy, Unrecovered War Casualties – Army, and Historic Unrecovered War Casualties - Air Force. As the names of these agencies suggest, Defence is not just concerned with shipwrecks, but most importantly with its historical unrecovered casualties. Australians served or were lost in the ships and aircraft of other countries which similarly claim ownership of their own UCH, but in which Australia might also claim an interest through its casualties, such as in Montevideo Maru.
Defence underwater cultural heritage sites around the world
This agreement formalises the requirement for consultation between DCCEEW and the relevant Defence agency regarding any activity involving Defence UCH around the world. And there is plenty of that. Australia has sovereign owned military UCH, or an interest through casualties in other state’s UCH, in the waters of at least 40 coastal states throughout the world, which is a third of those nations with a coastline. In fact, Australia owns more naval ships and military aircraft sunk in other countries’ waters than there are in all the museums in Australia. The underwater space is Australia’s largest military museum in this sense, as well as the last known location of around 6,000 of its casualties.
Importantly, there is no exhaustive list of UCH in this agreement because no service has one. Consider the many aircraft that did not return from missions and that may have been lost over land or sea; the Army casualties lost in the escape from Singapore – we are not sure who embarked in what vessel where; or the enormous amount of material expended and lost from Navy units over a century of service.
Within Defence, Navy has the most interest in UCH in the terms of the number of vessels lost, Air Force in the total number of sites given all the missing aircraft, and Army by the number of casualties involved.
The standards for how the Australian Government will treat Defence UCH outside Australian waters are now formalised through the Sovereign Wrecks Agreement. This agreement clearly outlines the expectations of all the agencies involved, and gives each guidance on how to approach an activity directed at Defence underwater cultural heritage. Where allowed – look and report, but don’t touch unless you are formally authorised through this agreement.