Australia's most recently retired navy chief warns the country's ageing Collins Class submarine fleet will become easier to detect in an increasingly crowded maritime neighbourhood because they need to surface more frequently than nuclear-powered boats.
Vice Admiral Mike Noonan, who ended his term in July, has given a frank assessment of the urgency for nuclear-powered submarines under the AUKUS partnership with the US and UK to replace Australia's current conventionally powered boats.
Appearing on an Australian National University podcast, Vice Admiral Noonan argues the longer endurance of nuclear submarines is a distinct advantage in an increasingly militarised and contested region.
"As we move into a more contested environment and systems in our region that make submarines more detectable when they're on the surface, the only way to remain undetected is to not be on the surface," the former chief explains.
"That periodic surfacing that typically occurs once or twice a day in a conventional-powered submarine does not need to occur in a nuclear-powered submarine, which of course restores our balance to use that strategic asset in the way the government should choose to."
Speaking to the ANU's Professor Rory Medcalf, the former navy chief explained the threat posed to diesel-electric submarines by the "greater level of surface and above-water surveillance capabilities by all nations, in particular by China in the South China Sea".
"So, our assessment would be that in the years to come, conventionally powered submarines would be detectable whenever they surfaced," he tells the ANU's National Security Podcast.
New submarine could combine best British and American attributes
In March next year, the Nuclear Powered Submarine Task Force is due to hand findings to government from an 18-month study examining the best options for Australia's future fleet.
Asked if he believed the task force would simply decide between a British Astute-class boat or an American Virginia-class submarine, Vice Admiral Noonan said it was becoming apparent there wasn't a "straightforward" choice.
"From my perspective, I think there's great advantages in the Astute, I think there's great advantages in the Virginia, but ultimately the decision of what the platform will be needs to best meet Australia's needs.
"I could see that it would be a combination of the advantages that both platforms bring — neither platform is perfect for Australia but they both have some very strong attributes.
"The final product could have attributes and features or systems that may come from the other design, or in fact new technologies that might be coming along."
Towards the end of his term as chief of navy, Vice Admiral Noonan publicly pushed back against calls for Australia to acquire a new interim submarine fleet to fill the capability gap between the scheduled retirement of the Collins Class and the arrival of new nuclear boats in the 2040s.
"I remain very confident, very confident that the Collins Class submarine will remain a very capable submarine that will continue to meet Australia's needs until we see the nuclear-powered submarine," he declared in May.
