To clarify some things about the contest:
The main thing we are after, is a good 3D Narwhal model.
We know that modders here will be able to tweak here and there the submarine, so it does behave like it should, have the proper range, weaponry, etc. Therefore, what we need most is to have it look like the real thing, so when in doubt, concentrate in the 3D model and don't worry that much about testing physics and behaviour.
Oh, and an Argonaut variant would certainly be interesting
Main difference is the elevated gun platform in the Narwhal/Nautilus vs. the standard guns on deck in the Argonaut, so the variant can in fact be created by just using the plain hull before the gun platform is modelled and added.
I will post ASAP in this thread plans and pictures of the Narwhal/Argonaut so that anyone interested can have material to start with