Maybe I'm missing something, but I had a sub that was Sunk by a heavy hit on the tactical display. OK, so I clear off the display and remove the ships already on it, but what do I do with them?
Are the cards for the ships that I encountered discarded for the purposes of the campaign (so I only encounter those ships in that combat and not in any others at least for this Campaign/Patrol), or are they reshuffled back into their decks so my other subs in other areas may have a chance to encounter them?
Also - if you draw a Convoy Card and choose to retreat rather than engage it, the U-Boat doesn't get 1 Stress because it didn't engage in combat, right? It only gets that Stress point after it leaves the tactical display (which it didn't enter this time)?
I think that once a card is used it is placed in a discard pile and remains there untill all cards of a type are used, when you form a new deck with the discarded cards. This is what the rules say: "After you have drawn the last card from a deck, gather the discards, and shuffle them to form a new deck".
This means that you may encounter again ships that you have alredy sunk, but it is not as bad as it may sound; consider these as ships of the same class (the actual name is unimportant).
As for Stress, correct. If there is no Combat Resolution Phase, then no stress is placed.