Navy warship fleet to double with $11b increase

An additional $11.1 billion will be pumped into Australia's combat fleet over the next decade, which covers the acquisition of 11 new general-purpose frigates.

There will also be six "optionally crewed" ships.

The troubled Hunter-class frigate program will be scaled back from nine ships to six to make way for general-purpose vessels.

The first Hunter will arrive in 2032 as scheduled but the general-purpose boats will be expedited to arrive this decade.

The first three general-purpose frigates will be built overseas so they're in the water faster before the rest are built in Perth.

The ANZAC-class frigates and Hobart-class destroyers will also get a facelift with new anti-ship and long range missiles as the Australian Defence Force looks to project itself deeper into the Pacific.

This includes replacing harpoon anti-ship missiles with naval strike missiles and installing tomahawks for long range.

But the government will not move to extend the life of the ANZACs, saying the new general-purpose frigates would be more lethal and cost effective given the navy can only crew less than six of the eight ships.

The first of the ageing class, the HMAS ANZAC, will be retired and not go back out to sea. The second will be mothballed in 2026, reducing the navy's total fleet in the near term until the early 2030s.

Larger warships will have a combat helicopter and undersea warfare capabilities with sonar and lightweight torpedos.

The overhaul will boost the combat fleet from 11 to 26 by the mid-2040s alongside a further 25 "minor war vessels".

The latter includes 14 for the navy - including six Arafura-class offshore patrol vessels - and a further 11 for the Australian Border Force.

The shake up will be underpinned by 3700 jobs in South Australia and Western Australia. It includes the continuation of 2000 jobs in SA and 500 new ones, as well as 1200 new ones in WA.

A major review of the navy's surface fleet made 18 recommendations and implored the government to move quickly.

"Any delay will exacerbate the risk (and) lead to a level of unbalance," the review said.

A continuous production line of ships will also be put in place to ensure there are no gaps in the future.

The changes would make the navy the most lethal it has ever been, Defence Minister Richard Marles said while unveiling the overhaul on Tuesday.

"Australia's modern society and economy rely on access to the high seas - trade routes for our imports and exports and the submarine cables for the data," he said.

Mr Marles also chastised the former coalition government for a more than $25 billion budget black hole through unfunded projects.

The cash splash will take the defence spend up to 2.4 per cent of GDP by the early 2030s.

An upgraded naval shipbuilding and sustainment plan will be released later this year.

Australian Associated Press