Following the recent announcement that Australia would acquire three submarines already in US service rather than two used submarines and one new one, AUKUS has again dominated headlines.

AUKUS is a defence capability agreement between the United States, the United Kingdom and Australia. Since it was announced in 2021, it’s rarely been out of the news.

But how much of what you have heard is true?

As a former Navy officer specialising in anti-submarine warfare, I am frequently asked the same questions about AUKUS. While I can’t address everything in one article, here are the details behind some of the most common claims.

Why is Australia buying used submarines?

Australia has Collins class submarines that entered service between 1996 and 2003. Work should already be underway to replace them, but decades of delays and underfunding have left us with an ageing fleet.

Though the Collins class submarines will each go through a multi-year maintenance period extending their life, they won’t last long enough. They will need to be decommissioned before Australia can co-design, build and produce submarines here under AUKUS.

A stopgap solution is required. The purchase of three Virginia class submarines in 2032, 2035 and 2038 will provide this, and also give Australia the ability to start operating nuclear-powered submarines.

Think of it as a “crawl, walk, run” approach. The Virginias are the walk phase before we start building our own nuclear-powered submarines.

Acquiring submarines already in service reduces risk and complexity, avoids the challenges of introducing a new submarine, and removes the need for initial certification trials.

Is Australia getting a less capable submarine?

Not in any meaningful sense, though the third Virginia will be an older version than planned, so its sensors will probably be slightly less........

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