Yes, Panther is correct. An important additional note is that the attacking transports may not unload during non-combat. Anything that is on board stays on board and remains vulnerable to sinking.
Enemy subs can be attacked or ignored at will by the acting player. The only effects that a destroyer has are to suppress subs special abilities and to allow air units to hit them.
‘sub’ stall is not a term we’ll be using in this game.
The only way to force combat or make a fleet stay is to drop a surface vessel. Most likely a DD.
If the defender has transports they cant be allocated as hits in any combat round. They are invisible and automatically removed from play provided the non-transports have been removed as combat loses. If the attacker does not stay long enough to kill the last combat ship the defending transports remain in place.
