[THEBERBSTER]

Hi SJC
Most missions (CW, NWA, SWA), are made up of 3 patrol areas where you have to mark out your area as stated in your orders and patrol that area for a length of time without making a game save.

BO is a useful entrance to the game where basically you only need to sink 2 ships to complete this mission.
The exceptions to this is where you are given a special mission to do such as in NWA , OW or other patrol orders as in OW which consists of attacking ships.

BTF is a poor mission with flawed AI and the only satisfaction is the tonnage total that you sink, but it really is just a turkey shoot.
BTF will usuually appear after you have requested CW which does not stop you doing it. In TWoS no mission is compulsory and all ships sunk are added to your tonnage totals.

CW is IMO only worth doing once due to being plagued by aircraft and as long as you sink a couple of ships in this mission will help your career promotion points build towards your VIIB upgrade.

NWA is worth doing more than once because of the AMC's and troop ship tonnages. These ships use Loch Ewe as their port.

SWA which is the furtherst mission you will have to travel to get to does finiish the Total Germany campaign.

While you might be tempted to do SWA I prefer to be around the NWA area so I am in an easier distance of OW which is a short mission and leave SWA to end the campaign on.

While you can get 3 promotion crew points for completing a patrol grid mission you only get 1 promotion point for doing special hazardous missions which IMO seems a bit unfair for the time it takes to do these lenghty missions. The only upside is you can make game saves as and when you want to.

It is worth noting that after OW finishes there is still time to do SWA which ends the Total Germany campaign.

You might find this helpful.
Open Horizons II > Campaign Dates > Bases > U-Boats > An Essential Guide
Peter