Sea mines: Australia’s most dangerous blind spot

26 May 2026 | Jennifer Parker

*Originally published in The Australian on 26 May 26

Image: 4.5 tons of Wold War II High Explosive is destroyed just off the coast of Bougainville during Operation RENDER SAFE 14. Defence Images.

Australia is an island nation with one of the world’s largest maritime domains, and its prosperity and ­security depends on seaborne trade, including fuel, fertiliser and pharmaceuticals.

Yet as Australia invests heavily in nuclear-powered submarines and an expanded surface fleet in the 2030s, a critical vulnerability remains: Australia has little real capacity to detect and clear sea mines.

Sea mines are the simplest way to shut down a port, a chokepoint or a coastal trade route. They can be laid at scale by dedicated vessels, but just as easily deployed by submarines, fishing boats or other vessels of opportunity and, increasingly, uncrewed systems.

As the Strait of Hormuz shows, even the suggestion of mines is enough to deter traffic. Iran’s warnings alone have kept most ships away, with the few transiting vessels steering clear of the traffic separation scheme, which Iran has declared mined, and hugging the coasts.

Australia’s coastal waters were mined during both world wars, first by a German raider and later by German raiders and Japanese submarines. The Royal Australian Navy also laid defensive mines to protect key ports and restrict submarine access.

After World War II, the Royal Australian Navy spent years clearing more than 1800 mines.

In 1947, HMAS Warrnambool was lost during these operations after striking a mine, with four sailors killed.

Australia’s geography makes it particularly vulnerable. Its large ­island mass and dispersed ports mean mining is a simple and effective way to shut down access.

The People’s Liberation Army – Navy is assessed to hold a vast inventory of sea mines, likely in the tens of thousands.

In any major Indo-Pacific conflict, Australian ports and key chokepoints such as the Torres Strait should be expected to be mined. Mines would stop our ports and coastal trade, and threaten the operation of our naval forces, ­including nuclear-powered submarines. Mines near HMAS Stirling would immediately halt operations at our only submarine base.

Given Australia’s experience during both world wars, and China’s vast sea mine inventory, mine clearance should be a priority. It is not treated as one.

Australia’s capability is in a parlous state, having been neglected for decades. This is not new. In 1989, the Joint Standing Committee on Foreign Affairs examined the threat mining posed to Australia and the capability required to respond.

It prompted a reinvigoration of mine warfare, including reorganisation and, critically, acquisition. The committee was clear that “the development of a capable mine countermeasures force must be one of the highest priorities for the ADF.”

Yet in 2026, while our geography and maritime dependence remain unchanged, the threat has grown. We have no strategic warning time, we face our most ­dangerous circumstances, and our mine warfare capability is marginal at best.

Of the six minehunters commissioned in the 1990s and early 2000s, only two remain. Both are over 20 years old, heavily used and nearing decommissioning. Their planned replacements and the deployable mine warfare capability under SEA 1905 were cancelled in the 2025 Integrated Investment Program, most likely due to budget pressures. The result is stark.

In 2026, Australia is left with two ageing minehunters and a small, Sydney-based team operating limited, largely experimental systems, including reportedly fewer than 20 uncrewed underwater vehicles and a handful of mine neutralisation systems.

Mine warfare received little ­attention in the 2024 Integrated Investment Program, and the cancellation of future capability has been met with claims it will be solved by autonomy. Uncrewed systems will shape parts of mine warfare, but without a clear plan or platforms to deploy them from, that promise is hollow. Beyond port clearance, these systems still need to operate from a vessel, and the last suitable platforms are nearing decommissioning. “Vessels of opportunity” lack the hardening and signature management required to operate in or near a minefield. Advances in autonomy reduce risk, but do not remove the need for vessels.

The Royal Australian Navy needs deployable mine clearance capabilities that make use of ­advances in uncrewed systems, but it also needs dedicated vessels to operate them from. Yet the latest Integrated Investment Program expands its discussion of mine warfare without allocating funding to a capability identified as a top priority more than three decades ago. The point is simple. ­Nuclear-powered submarines are of little use if the waters outside their ports are mined.

Beyond capability, Australia needs a concept of operations, as recognised in the 1989 Senate inquiry. Mine warfare must be distributed and responsive. It is of little use concentrating capability in Sydney if Port Hedland is mined. Australia needs deployable mine warfare teams and key capabilities positioned across both coasts. This is well suited to a model supported and augmented by a reinvigorated Naval Reserve.

Australia’s ports, coastal trade routes and Pacific partners are vulnerable to mine warfare. As in the past, in any regional conflict Australian waters should be expected to be mined. Despite having no strategic warning time and facing our most dangerous circumstances since World War II, Australia has little more than a token capability to respond. That must change, and quickly.