Here is my first attempt for a Interwar/WW2 period submarine for my AU nation. It is supposed to be the first design built for that country and is primarily intended to act as a scout and coastal defense vessel mostly within the Bering Sea with possible use in the North Pacific against IJN vessels (if war was to arise between the two nations which is possible as tensions are high).
This particular class is small and relatively lightly armed with two 21' forward torpedo tubes and a single aft tub firing between the twin screws. I would sim this in springsharp if I knew how but I'm assuming it's probably only going to have a diving depth of about 100ft and a max surface speed of about 14-16 knots. Not sure of the precise construction date yet but the craft are supposedly the predecessors to the later ocean-going C Class submarines which entered service in 1938.
Any and all critique is welcome.