Stealth Submarine "Ghost Shark".

Australia's government said the Ghost Shark is a "game changer" as it unveiled its first prototype. The lethal-looking sub - roughly the size of a single-decker bus - will be able to reach a depth of 6000 metres, and be able to stay on a mission for up to 10 days.

Defence scientists, Navy personnel and robotics specialists are working together to design several XL-AUVs that will be deployed to fortify ocean patrols and protections.

It will provide its Navy with a “stealthy, long-range autonomous undersea warfare capability” and will conduct “persistent intelligence, surveillance, reconnaissance and strikes”.

Praising the prototype, Navy chief, Vice Admiral Mark Hammond, said Ghost Shark was crucial to Australia's defence.

He said: “We are a nation girt by sea, and the Ghost Shark is one of the tools we are developing for the Navy to patrol and protect our oceans and our connection to the world,” he said.

By creating the Ghost Shark, Defence Industry Minister Pat Conroy said that "a clear statement is being made about Defence’s commitment to the program."

The government stated that the project would be "mission zero" meaning it would be the highest-level of priority - and it hopes the Ghost Shark will be ready for deployment in 2025.