Well said and think of all the diesel saving,s over the life of the submarines ......that alone would pay for the subs over their lifetime..... ( a double win situation)
The sub if Australia got them could sail submerged from Sydney to London submerged non stop and undetected and drop in for a cup of Tea and a few crumpets and more supplies then head over the top of Russia undetected and down the bering straight to seattle or San Diego. say hello and then down the east coast of south America and head back across the ocean via whatever island you like and return home and the fuel cost would be NIL...... just food needed...
You could follow anyone for months on end without a re-fueling ship or post needed to give away your position.....
