It's working!
Thank you guys for your help, I'm now docked at Peral Harbour ready to set off on my first patrol in FOTRSU.
To Fix my issue I deleted the SH4 folder in the users\documents folder then I ran the 4GB Patch program and that's all it needed.
To go over my install in case anyone else finds it a fairly mammoth task;
Download the JSGME mod enabler (links are all in the FOTRSU thread). You then need to set the
Start In folder to where your SH4.exe is located. Right-Click your JSGME icon on your desktop - properties - Start In (In my case this is what I put in - "E:\Steam\steamapps\common\Silent Hunters Wolves of the Pacific")
Then I installed the mods in this order using JSGME;
100_Falloftherisingsun_ultimate_v1.8 (This can take a few minutes)
101_Fotrsuv18_FixPak
FI-OQ_Fotrsuv1.8f_upcPatch
I then deleted the folders in the SH4 folder - C:\Users \UserName \Documents \SH4
I then downloaded the 4GB Patch (From
https://ntcore.com/?page_id=371) and ran it on the SH4 executable in my steam folder (I suspect it was this part here that was my issue).
Thanks again for the help now let's hope nobody sinks my boat!

