[sukhoi-30mki]

Source: NewsCorp

[sinsofsolarempirefan]

Thats an old fashioned propeller right there. Must be quite noisy.

[MasterGunner01]

The Australians should look long and hard at AIP (air independent propulsion) in their new diesel-electric submarine. This is a real game changer over a conventional boat. The AIP function allows you to run the diesels while submerged for greater speed and not deplete the batteries as you would in a conventional sub.

The Aussies are looking at a submarine replacement for their Collins-class boats that will be about twice the displacement and around 90 meters in length. Range should be as good as the Collins-class or improved. The Japanese Soryu-class falls short in range behind the Collins-class, Type 216, or Barracuda-class boats.