The boat was a XVIII, a Large combat version of a Walter boat. Lot fewer crew but a lot more fish, all inside.
I decided to recreate an alternate reality stream in which I took the XVIII
I'm just going back and starting the adventure but the thing can be a fuel pig!
Didn't understand the turbine controls on my first try and ran low on fuel less than half way to my destination am going back to refit and try again.
Thanks for the
http://uboat.net/types/xviii.htm link though. I can use it to research any other boats I come across