Thank you for the comprehensive reply K-61! One of my questions was going to be around mixing mods, but it sounds like that is not recommended. I have actually got the GWX expansion already, my game came with it on Steam. I also notice on the stickies that there is S3F which allows you to install multiple versions of SH3 with different mods, so from this I can ascertain that it is generally not recommended to mix any mods, unless you know what you're doing (as you say) or were you just talking about the Super Mods?
It's funny, an old colleague told me about newer Silent Hunter's. I got addicted to Silent Hunter 2 many years ago and when he mentioned Silent Hunter 5 I knew I had some catching up to do. But he also tells me 3 is still considered to be the best gameplay wise, so I'm definitely looking forward to getting stuck in. Like you said, already the learning curve seems great.
I think I am going to take your advice and play on GWX without any other mods for now, to get used to things before I start looking into what I want to mod in the game. Although out of interest, could you let me know what mods you would recommend for adding realism please? I would much rather play an authentic u-boat game, I'm not into your "Call Of Duty" style shoot-em-up. I want realism!
Mnay thanks again,
Jamie.