Subs From Down Under: Meet Australia’s Collins-Class Submarine These submarines were developed to travel distances while also being able to operate in varying environments from cool southern oceans to warm, shallow tropical waters. In December 2020, the Royal Australian Navy (RAN) announced that its six domestically-built diesel-electric Collins-class submarines would be upgraded with the new Thales sonar systems. The Australian government would invest $23.7 million on the upgrades, which will reportedly increase the operational effectiveness of the boats in hazardous, shallow waters through the installation of the sovereign Mine and Obstacle Avoidance Sonar and High Frequency Intercept Array systems developed by Thales Australia.