Australia considers German Type 214 submarine option.

According to information published by ABC News on June 1, 2021, the Australian Navy is considering the Type 214 submarine built by the German firm ThyssenKrupp Marine Systems before the delivery of the Attack-class submarine program expected to enter service in the early 2030s.
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Hellenic Navy's Type 214 submarine (Picture source: Hellenic Navy)

The Type 214 is a diesel-electric submarine developed by Howaldtswerke-Deutsche Werft GmbH (HDW). It features diesel propulsion with an air-independent propulsion (AIP) system using Siemens polymer electrolyte membrane (PEM) hydrogen fuel cells.

The class is exclusively designed for the export market. The submarine class combines the design principles of the Type 209 family and the features of the Type 212A submarines. However, as an export design, it lacks some of the classified technologies of the smaller Type 212, the most important of which is probably the non-magnetic steel hull, which makes the Type 212 submarine difficult to detect using a magnetic anomaly detector.

Due to improvements in the pressure hull materials, the Type 214 can dive nearly 400 meters (1,300 ft). It can also carry food, fresh water and fuel for 84 days of operation.

The Type 214 submarine is approximately 65 meters (213 ft) long, and has a maximum submerged speed of at least 37 kilometers per hour (20 kn; 23 mph). It has a crew of 27 people including 5 officers and 22 sailors.

Air-independent propulsion (AIP), or air-independent power, is any marine propulsion technology that allows a non-nuclear submarine to operate without access to atmospheric oxygen (by surfacing or using a snorkel).