Missions?
 

I have completed all of the objectives in North Western Approaches, 26/01/1940 and was told by BDU to return to port but use any torpedoes before returning.
I ended patrol when back in base but now have two months before the end date is it best to just go out and sink any permitted ships, start a new mission South Western Approaches or advance time if that is possible?
Also is there a set date when I get a new submarine?

I believe another objective comes available around March. I got my new sub after doing a couple of patrols on the British Coastal Waters mission. Each time the Orange patrol marker would vanish and I used up my torps, I would go back to the Sub Pens and end the patrol. Choose the same mission again for a new patrol marker and rinse/repeat for ludicrous amounts of Renown.

Hi Scorpion
Not knowing the exact date of your patrol end which seams that you are in February 1940.
SWA starts in January 1940 and lasts for 5 months so you should be able to start that one now.
There is nothing to stop you continuing with NWA for the next 2 months as it will drop off the map when the date passes, this would set you up quite nicely for the Norwegian Campaign starting in the 3rd week of March and only lasts for 3 weeks. This would still leave you with over 2 months to do the SWA.
You can accept any mission as many times as you want to, the advantage being with the NWA mission is the larger AMC's based in Loch Ewe which will bolster your tonnage considerably.
U-boat upgrades in the Total Germany Campaign I believe are based on the tonnage totals. The more tonnage you sink the quicker you will upgrade from a VIIA to VIIB.
These are the stock game default minimum requirements.
EBCW = 70,000 tons
NWA = 80,000 tons
OW = 2 objectives 5 ships + 2 ships
SWA = 90,000 tons
If you are going to do SWA then the VIIB will make a difference as you have a long trip back to rearm.
Peter