thanks for the many replies...
DivingDuck-
yup, i have maya as my 3d app and it will export .obj files, also photoshop for textures.
any ideas where i can find pack3d, it is free right? or do i have to dust off my credit card! i googled it but just came up with a multitude of russian forums
one thing would worry me about making open compartments, the polycount, having the rest of the sub as one big `fake` compartment would mean that it would all have to be drawn by your vid card at the same time, so id probably have to make each room less detailed to keep the count low. With closed off compartments i could go to the max number of polys allowed in each and hence have a much better looking sub.