Hi Greystone when leaving the channel ports 1942-43 onwards as soon as you have enough water under your keel dive to periscope depth in a type VIIB/C 13 meters and depth under keel will be 3/4 meters sweet head to your patrol grid.
At 3knts no more use time compression but mindful of batterie level and air for your crew you don't want them to suffocate through lack of air once your in the BF grids 11/19 north west of Ireland surface
and recharge your batteries use time compression 32-64x no more or you wont see the aircraft coming and your a dead duck.
Also try to time your recharge always early hours of the morning 1:00am - 3:00am and dive to periscope depth before dawn.
A full Batterie Charge completed at 2:30-3:00am then diving to periscope depth continuing to patrol grid at 3knts would give you 18/20 hours batterie time so your able to surface again in the early hours
When out in the Atlantic and you need Fuel and Torpedo reloads head for the Milkcows in the Atlantic
the Atlantic is a big place to hide in only go back to your home Port Lorient St Nazaire if you need Critical Repairs like a new Engine or Replacing 6 dead crew.
Hope this helps you some
Attacking Convoys Mid 1942 onwards
the days are over when you could slip inside the thin Convoy Screen get inside the Convoy and pick the best targets.
The Allies now have better Escorts and there are more of them protecting convoys 9-18 escorts so any Uboat Commander worth is salt shouldn't put himself or his Uboat and Crew to any unnecessary risk without the good prospect of inflicting greater damage to the Enemy.
The Standoff Attack
Approach Broadside of Convoy Port or Starboard as situation dictates creep toward the convoy at two knots then turn on a parallel course to Convoy when you get to 800-1200 meters from nearest line of merchants.
Don't attack them yet target ships in the fourth-third line from you and then the second line from you then fire your last Torpedo from your stern tube firing at the furthest targets first when the Torpedoes strike home on ships in the middle of the Convoy the Escorts will go to that area doing sonar sweeps looking for you and as other Torpedoes find their mark the Escorts think theres more than one Uboat attacking so you have confused the escort screen.
Then creep away you don't want to stick around you only have to worry about the two or three escorts on your side of the Convoy nearest to you the other escorts are too far away unless you stick around reloading for a second crack at the Convoy
making noise reloading play to your strengths be stealthy silent and deadly never push a bad position.
