Stealthy submarine drones will bolster the Australian navy, allowing it to expand surveillance and increase long-range strike power.
The federal government has put $1.7 billion toward the Ghost Shark, with the first tranche to arrive in January 2026.
An exact number hasn't been publicly stated, but Defence Minister Richard Marles said it would be in the dozens over five years.
"This is the highest tech capability in the world, it exemplifies the fact that Australia is leading the world in terms of autonomous underwater military capabilities," Mr Marles told reporters at Sydney's Garden Island naval base on Wednesday.
The drones will operate alongside Australia's naval fleet and can be used with its submarines, including nuclear-powered vessels it will acquire from the United States in the 2030s.
Navy chief Mark Hammond said the Ghost Shark could be launched from shore and from warships.
The vice admiral said he was confident Australia and its allies "will continue to enjoy a capability advantage" in undersea warfare as nations such as China develop sophisticated drones and submarine detection technologies.
"My personal belief is that the undersea battle space will continue to be increasingly congested, increasingly contested," he said.
Mr Marles added while there were advancements in submarine detection technologies, "there's also a lot of advancements in technologies around making submarines harder to detect" when asked about China's latest military showcase.
"What is clear is that going forward, nations will need to have an autonomous underwater military capability and that's what Ghost Shark represents," he said.
Mr Marles said details about the drone were being purposely kept vague.
"We're going to be a little coy in terms of how we answer specific questions about what this can do, given the nature of what it does," he said.
"This is a capability which will be able to engage in intelligence, surveillance, reconnaissance and strike, and one should read those words to the fullest extent."
Anduril Australia is in charge of the delivery, maintenance and continued development of the Ghost Shark as part of a five-year contract.
The underwater drones will be built in Australia.
