Yes, there are transfers available, but sometimes restrictive. Let me make sure I understand where and when you are: Lorient in 1942 - correct? Where are you wanting to transfer to?
The main reason you won't be allowed to transfer (besides a particular base not being available at the time) is that the flotilla has to have the same boat you are driving available where you want to transfer to. If you know how to look through the CareerStart and Flotillas files, you can "see" what boats are available in the different flotillas. The numbers displayed in the game do not match the numbers in the files, although there is a "NameDisplayable=..." line that would have the "real" name of the flotilla, so you could search on that. The files though are a bit strange. Rather cryptic. Do not save any accidental changes you might happen to make
...
